• <tr id="yyy80"></tr>
  • <sup id="yyy80"></sup>
  • <tfoot id="yyy80"><noscript id="yyy80"></noscript></tfoot>
  • 99热精品在线国产_美女午夜性视频免费_国产精品国产高清国产av_av欧美777_自拍偷自拍亚洲精品老妇_亚洲熟女精品中文字幕_www日本黄色视频网_国产精品野战在线观看 ?

    High-efficiency Gas Shielded Multi-arc Welding Technology

    2016-12-12 02:42:24TANGYingyingZHUZhimingYANGZhongyuYUYingfei
    電焊機(jī) 2016年11期
    關(guān)鍵詞:電焊機(jī)高效化電弧

    TANG Yingying,ZHU Zhiming,2,YANG Zhongyu,YU Yingfei

    (1.Department of Mechanical Engineering,Tsinghua University,Beijing 100084,China;2.Key Lab.for Advanced Materials Processing Technology,Ministry of Education,Tsinghua University, Beijing 100084,China)

    High-efficiency Gas Shielded Multi-arc Welding Technology

    TANG Yingying1,ZHU Zhiming1,2,YANG Zhongyu1,YU Yingfei1

    (1.Department of Mechanical Engineering,Tsinghua University,Beijing 100084,China;2.Key Lab.for Advanced Materials Processing Technology,Ministry of Education,Tsinghua University, Beijing 100084,China)

    Gas shielded multi-arc welding has a more reasonable distribution of arc heat and force than conventional gas shielded single-arc welding by means of the interaction between different arcs,and thus can get better weld quality.It has become an important way to achieve high efficiency for gas shielded arc welding at present.Moreover,compared with other new types of high efficiency welding methods,such as laser welding,laser-arc hybrid welding,electron beam welding,friction stir welding,etc.,gas shielded multi-arc welding has lower welding cost,more complete auxiliary facilities and stronger adaptability,so it has significant industrial application value and broad development prospect.In this paper,according to the process modes of single-sided or double-sided welding and the different combinations of electrodes,the principles,characteristics and applications of typical gas shielded multi-arc welding technologies are first introduced,then their existing problems are analyzed,and finally their future development directions are discussed briefly.

    gas shielded arc welding;high efficiency;multi-arc;heat-force distribution;deposition efficiency

    0Introduction

    As the rapid development of modern manufacturing industry has an increasing requirement for high efficiency welding,developing high quality and high efficiency welding technology has become one of the key issues which need to be solved urgently at present by welding researchers[1-2].

    Conventional gas shielded single-arc welding,including Gas Metal Arc Welding(GMAW or MIG/MAG),Gas Tungsten Arc Welding(GTAW or TIG),Plasma Arc Welding(PAW),etc.,is widely used for metal joining in industrial production because of some obvious advantages,such as low welding cost,good applicability,convenient to monitor the open arc,easy to achieve automatic welding.If its welding efficiency could be improved further,it will bring in considerable economic benefits.However,restricted by the single arc,conventional gas shielded single-arc welding cannot constantly improve its welding efficiency to achieve high efficiency welding by unlimitedly increasing the welding current.This is because the distribution of single-arc heat and force will become over-centralized when the welding current is too high,which easily causes such weld defects as burning through,undercut,and even humping bead in high speed welding of the thin plate.In addition,when the welding current is too high,the mode of the droplet transfer in GMAW will turn into uncontrollable rotating spray transfer,which deteriorates seriously the stability of the welding process[3].In order to solve these problems,some scholars have developed various types of gas shielded multi-arc welding technologies with the method of multiple electrodes instead of the single electrode in recent years.By means of the interaction between multiple arcs,gas shielded multi-arc welding can improve the distribution of arc heat and force,the fluidity of liquid metal in molten pool,increase the deposition efficiency of the welding wire.As a result,the welding efficiency of gas shielded multi-arc welding can be increased further[1-2,4].

    In this paper,according to the process modes of single-sided or double-sided welding and the different combinations of electrodes,the principles,characteristics and applications of typical gas shielded multi-arc welding technologies are first introduced,then their existing problems are analyzed,and finally their future development directions are discussed briefly for the expectation to have some positive effects on the development and generalization of gas shielded multi-arc welding technology.

    1Single-sided multi-arc welding

    For single-sided multi-arc welding,there are the combinations of same types of electrodes,such as multielectrode TIG welding[5],multi-wire GMAW[6],and the combinations of different types of electrodes,such as DEGMAW[7],Plasma-MIG hybrid welding[8]and TIG-MIG hybrid welding[9],etc..

    1.1Multi-electrode TIG welding

    The main features of multi-electrode TIG welding are that multiple mutual insulated tungsten electrodes(instead of the single tungsten electrode)are installed in one welding torch,and each of them is connected to an independent power supply.The welding parameters of each power supply can be adjusted independently,because each tungsten electrode is in the different welding circuit loop.Therefore,multi-electrode TIG welding has good flexibilityand adaptability[5].Accordingtothe number of tungsten electrodes,multi-electrode TIG welding isclassified into dual-electrode TIG welding(Fig.1)and tri-electrode TIG welding[10].By contrast,dual-electrode TIG welding has more research and application due to relatively simple system structure.

    Fig.1Schematic illustration of dual-electrode TIG welding

    In dual-electrode TIG welding,two tungsten electrodes have the same polarity,(that is,the welding currents flowing through two arcs have the same direction),so a stable coupling arc can be formed by electromagnetic attractive force between arcs.It can be seen that dual-electrode TIG welding retains the advantages of conventional single-arc TIG welding,such as good arc stability and high welding quality.Moreover,dual-electrode TIG welding can also get different coupling-arc shapes and the distribution of arc heat and force to match different welding requirements by adjusting the space and angle between two tungsten electrodes,and the welding current flowing through each arc,as shown in Table 1.It can be found from Table 1 that,when the welding currents flowing through two tungsten electrodes are equal,the coupling-arc shape is symmetric;otherwise,the coupling arc deflects to the side of the arc with the lower welding current[11].

    Table 1Coupling-arc shape of dual-electrode TIG welding

    Compared with conventional single-electrode TIG welding,when their welding currents are equal,dualelectrode TIG welding not only has less burning loss of tungsten electrodes by the shunting action of two tungsten electrodes,but also has smaller change gradient of arc cross-section area,which greatly reduces arc pressure acting on the surface of the molten pool(Fig.2).Therefore,dual-electrode TIG welding can improve its welding speed further.In other words,when their arc pressures are equal,dual-electrode TIG welding can increase its welding current to improve the deposition efficiency of the filling wire[11].In a word,dual-electrode TIG welding has the advantages of less burning loss of tungsten electrodes,higher welding heat input,welding speed and deposition efficiency of the filling wire.So it is suitable for high speed welding or high deposition efficiency welding,and can be used for the welding of metal materials with bigger thickness than conventional singleelectrode TIG welding.The previous research has shown that the maximum welding speed,deposition efficiency and weld penetration of dual-electrode TIG welding have reached 1.5 m/min[12],5.4 kg/h[5]and 6~8 mm[11],respectively. Besides,theweldingefficiencyofdual-electrodeTIGweldinghasbeenat least1.2 timesmore than that of conventional single-electrode TIG welding.

    Fig.2Arc pressure distribution

    As shown in Table1 and Fig.3,by controlling the pulse currents flowing through two tungsten electrodes to make coupling arc deflect properly,dual-electrode TIG welding can be well used for all position welding.Japanese IHI Co.Ltd adopted this method with hot filling wire instead of submerged arc welding to conduct the all position welding of liquefied natural gas storage tank with the maximum thickness up to 50 mm.As a result,not only was welding time shortened,but also weld quality was greatly improved[5].

    Fig.3Pulse current control of dual-electrode TIG welding

    1.2Multi-wire GMAW

    Multi-wire GMAW refers to the GMAW with multiple wires for welding at the same time.Compared with conventional single-wire GMAW,multi-wire GMAW can not only increase the total welding current without droplet transfer into rotating spray transfer to improve the deposition efficiency of the wires by the shunt action of each wire,but also homogenize the distribution of arc heat and force in different zones of molten pool to improve the fluidity of liquid metal in molten pool because multiple arcs share one molten pool,which is beneficial to avoid such welding defects as undercut or humping bead in multi-wire GMAW with high current and high speed[13-15]. Besides,in multi-wire GMAW,many welding parameters can be adjusted independently and each wire can be selected with different diameters and materials to adjust the chemical composition of the weld metal for the special requirements of joint properties.Furthermore,multi-wire GMAW has a larger size of weld pool and longer solidification time than conventional single-wire GMAW,so gas escapes from the molten pool more easily in multi-wire GMAW.Although there are more welding heat input per unit time in multi-wire GMAW,its heat input per unit length is not obvious higher than that of conventional single-wire GMAW because of its higher welding speed.In general,small welding deformation and high welding quality can be get in high speed multiwire GMAW[13-15].

    So far,multi-wire GMAW has been applied to such fields as car,ship,locomotive vehicle,pressure vessel and power generation equipment for the welding of carbon steel,low alloy steel,stainless steel,aluminum alloy and other metallic materials.However,restricted by the complex system structure of multi-wire GMAW,only double-wire GMAW(e.g.,TWIN ARC welding and TANDEM welding)is often used in industrial production[16].

    The main features of TWIN ARC welding are that two welding wires share one conduct tube and are usually powered by one high power supply,as shown in Fig.4a.The system structure of TWIN ARC welding is relatively simple,but its arc stability is completely determined by the self-adjusting ability of two arcs.Because of the strong electromagnetic interference between two arcs,it is difficult to select the proper welding parameters to control the arc length and droplet transfer of each wire accurately.As shown in Fig.4b,the main features of TANDEM welding are that two wires are fed through two mutual insulated conduct tubes and powered by two power supplies,respectively,so the welding parameters of each wire in TANDEM welding can be adjusted independently,and thus it is relatively easy to control the arc length and droplet transfer of each wire accurately. Compared with TWIN ARC welding,TANDEM welding has a more complex system structure,but it can get higher welding efficiency,better weld quality and stronger adaptability.TANDEM welding has become the most mature and widely used double-wire GMAW technology at present[16].Experimental results shown that the highest welding speed and deposition efficiency of the wires in TANDEM welding have reached 6 m/min and 36 kg/h,

    respectively[17].

    Fig.4Double-wire GMAW system

    Different from multi-electrode TIG welding,the electromagnetic attractive force between two arcs in multiwire GMAW will aggravate the instability of the arcs,even extinguish the arcs,and generate the irregular droplet transfer,which results in more welding spatter,and deteriorates the weld quality[18-19].In order to solve these problems,pulse welding(Fig.5)is commonly used in multi-wire GMAW.Among them,the pulse welding with same frequency and opposite phase(Fig.5b)can minimize the electromagnetic attractive force between two arcs and get the relatively most stable arcs and droplet transfer.Therefore,it has become the most commonly used working mode in doublewire GMAW[15].Moreover,one droplet transfer per pulse can be achieved by setting up proper pulse currents in this working mode,as shown in Fig.6,which is often used for the welding of aluminum alloy and stainless steel[16].

    Fig.5Pulse current waveforms for double-wire GMAW

    1.3DE-GMAW

    Non-consumable DE-GMAW first proposed by Zhang Yuming et al.is shown in Fig.7.Its main features are that a bypass GTAW torch is equipped to the side of main GMAW torch,and each of them is powered by an independent power supply[20].During welding,the melting current Imthat flows through and melts the welding wire is divided into two parts within arc column region:the bypass current Ibpand base metal current Ibm.The former flows from the welding wire to tungsten electrode of bypass GTAW torch,and the latter flows from the welding wire to

    the base metal.In this way,we can raise the deposition efficiency of GMAW wire by increasing the melting current Im,and simultaneously adjust the bypass current Ibpto get proper base metal current Ibmindirectly for getting the desirable heat input of base metal.Therefore,good weld quality can be guaranteed in high current DE-GMAW.It can be seen that non-consumable DE-GMAW is a welding process with high deposition efficiency of the wire and low heat input of the base metal.So it is very suitable for the welding of high strength steel or thin plate,overlay welding of wear-resistant or corrosion-resistant materials and so on[21].

    Fig.6One droplet transfer per pulse in TANDEM welding

    Fig.7Non-consumable DE-GMAW system

    Based on the same shunting principle of bypass arc,some researchers have successively developed nonconsumable TE-GMAW(triple-electrode GMAW),consumable DE-GMAW and pulse non-consumable DE-GMAW in recent years.Compared with non-consumable DE-GMAW,non-consumable TE-GMAW can homogenize the distribution of arc heat and force by installing two bypass GTAW torches on both sides of main GMAW torch symmetrically,which raises the arc stability of non-consumable TE-GMAW.Consumable DE-GMAW makes full use of bypass current to melt the bypass GMAW wire by using the bypass GMAW torch instead of the bypass GTAW torch,which improves the deposition efficiency of GMAW wire.Pulse non-consumable DE-GMAW further reduces the heat input of the base metal by the pulse current instead of the constant current[21-22].

    The previous research has shown that,except the shunt action for main GMAW arc,bypass arc can also promote the extension and jumping-up of main GMAW arc,which is helpful to decrease the critical current of non-contact droplet transfer of the main GMAW wire,and reduces the coupling-arc pressure.Therefore,such weld defects as undercut or humping bead can be avoided in high-current and high-speed DE-GMAW.However,the behavior characteristic of the coupling arc and droplet transfer in DE-GMAW is more complex than that of conventional single-arc GMAW,which makes it more difficult to get the stable welding process,especially consumable DE-GMAW.This is because the bypass power supply in consumable DE-GMAW is a constant current source,which weakens the self-adjusting ability of the bypass arc.In order to get the stable consumable DE-

    GMAW process,we need to adopt"arc length-bypass current"double closed-loop control.Moreover,as shown in Fig.8,the bypass arc in consumable DE-GMAW always tends to seek metal oxidation film and climb up along the bypass GMAW wire because the bypass GMAW wire is connected to the negative electrode of the bypass power supply.When pure Ar as shielding gas is used in consumable DE-GMAW,the main mode of the droplet transfer is globular repelled transfer,which aggravates the instability of consumable DE-GMAW process.But,if some oxidizing gas is added in pure Ar,coupling-arc stability will be raised and the mode of the droplet transfer will change from globular repelled transfer to spray transfer in consumable DE-GMAW[21-22].

    Fig.8Droplet transfer modes in consumable DE-GMAW

    1.4Plasma-MIG hybrid welding

    Plasma-MIG hybrid welding is a kind of double-arc hybrid welding technology with the high energy density of the plasma arc and the high deposition efficiency of the MIG wire.According to the relative position of the plasma arc and MIG arc,plasma-MIG hybrid welding is classified into coaxial plasma-MIG hybrid welding and paraxial plasma-MIG hybrid welding,as shown in Fig.9[23].The former has two types of bias tungsten electrode and ring-shaped copper electrode.By contrast,coaxial plasma-MIG hybrid welding with ring-shaped copper electrode has more practical application in industrial production because its ring-shaped copper electrode can be cooled easily by water and its welding torch has longer service life and better current carrying capacity[24].

    Fig.9Plasma-MIG hybrid welding system

    As shown in Fig.9a and Fig.10a,for coaxial plasma-MIG hybrid welding,its plasma arc and MIG arc are coaxial and burn in one welding torch,and thus can form a stable coupling arc due to both of them sharing the same conductive environment.Restricted by the plasma nozzle,the wire extension of coaxial plasma-MIG hybrid welding is bigger than that of MIG welding.During welding,the bottom of the welding wire,metal droplet and MIG arc are all surrounded in plasma arc and shielding gas.As a result,the protective effect of shielding gas is improved significantly,which greatly reduces the weld porosity and welding spatter.Besides,MIG wire is heated by the MIG arc and plasma arc together,and thus its melting rate is greatly accelerated.For example,the deposition efficiency of mild steel wire with the diameter of 1.6 mm can be up to 30 kg/h.Furthermore,the plasma arc is further concentrated under the action of magnetic field created by the MIG current,which enhances the stiffness and energy density of the coupling arc[8].Spectral analysis found that the outer temperature of the coupling

    arc(about 13 000 K)is higher than the inner temperature of the coupling arc(about 7 000 K),which is beneficial to homogenize the liquidity of liquid metal in molten pool and avoid weld defects in plasma-MIG hybrid welding with high current and high speed[25].

    Fig.10Arc characteristics of plasma-MIG hybrid welding

    Generally,themodeofDirectCurrentElectrodePositive(DCEP)isadoptedincoaxialplasma-MIGhybridwelding. This mode can break metal oxidation film on the surface of the workpiece by the cathode atomizing action of the plasma arc,and thus is especially suitable for the welding of easily oxidizable metals(e.g.,aluminum alloy and magnesium alloy).Besides,the strong preheat action of the plasma arc to the workpiece makes coaxial plasma-MIG hybrid welding have obvious advantages for the welding of the metal materials with good heat conductivity(e.g.,copper alloy and aluminum alloy)and underwater welding.However,coaxial plasma-MIG hybrid welding also has some deficiency,for example,the plasma arc and MIG arc burn in one welding torch,which has a strict requirment on the cooling ability of the welding torch.As a result,the size of the corresponding welding torch is larger than that of the conventional PAW or MIG torch.In addition,the most common way of arc ignition in coaxial plasma-MIG hybrid welding is soft starting arc by MIG wire being fed and then pulled back,but the reliability and stability of arc ignition remains to be further improved[8,26].

    Paraxial plasma-MIG hybrid welding is also referred to as Super-MIG welding,as shown in Fig.9b.The plasma arc and MIG arc have a certain angle along welding direction.When the welding starts,the plasma arc is firstly ignited as a guiding arc,and then the MIG arc is ignited.By the good penetrating ability of the plasma arc,a dynamic keyhole on the surface of the workpiece(Fig.10b)is formed,and the MIG wire is melted rapidly under the heating of the plasma arc and MIG arc together and filled into the dynamic keyhole,thus forming a deep-penetration and high-quality weld.Compared with coaxial plasma-MIG hybrid welding,the most advantage of paraxial plasma-MIG hybrid welding is that the requirement on the cooling ability of the welding torch is reduced,which makes the structure of the welding torch become compact and can realize the miniaturization and practicality of the welding torch.Paraxial plasma-MIG hybrid welding is often used for the welding of bigthickness or medium-thickness metal structural components[23].

    1.5TIG-MIG hybrid welding

    When MIG welding with pure Ar as shielding gas is used to weld stainless steel,the cathode spots of the MIG arc often jumps around for seeking the metal oxidation film,and the high viscosity of the metal droplet and liquid metal in molten pool easily causes such weld defects as curving weld bead(Fig.11),undercut and porosity. Therefore,a small amount of O2or CO2is often added in pure Ar to improve the weld appearance,but it results in the oxidation of the weld surface and reduces the mechanical properties of the weld joint[3].In order to solve these problems,TIG-MIG hybrid welding process(Fig.12)is proposed by Shuhei Kanemaru et al..The front TIG arc,

    which exists persistently,can not only preheat the MIG wire and workpiece,but stabilize the cathode spots of the MIG arc in pure Ar as shielding gas.As a result,not only can TIG-MIG hybrid welding get good weld appearance and deep penetration(Fig.11),but also its weld quality is equivalent to that of TIG welding.It can be seen that TIGMIG hybrid welding has the high weld quality of TIG welding and the high welding efficiency of MIG welding[27-28].

    Fig.11 Performance comparision of two welding processes

    Fig.12TIG-MIG hybrid welding system

    Because of the opposite polarity connection of TIG welding and MIG welding,there are two kinds of interaction between TIG arc and MIG arc,as shown in Fig.13:(1)Electromagnetic repulsive force(i.e.F and F'),caused by the opposite current directions of two arcs;(2)Electromagnetic attractive force,caused by the high potential difference(i.e.U1+U2)between MIG wire and tungsten electrode.Under the influence of above-mentioned two forces,TIG arc and MIG arc are coupled and eventually form a stable coupling arc under a certain conditions.Besides,coupling arc can homogenize the distribution of arc heat and force acting on the surface of molten pool,so various weld defects can be avoid in TIG-MIG hybrid welding with high current and high speed[29-30].

    2Double-sided arc welding

    When conventional single-arc welding is used to weld big-thickness or medium-thickness metal structural components,proper groove has to be machined and multi-layer and multi-pass welding must be performed because of the poor penetration capability of conventional single arc.Consequently,it not only reduces the welding efficiency and increases the production cost,but also cannot guarantee the joint quality.In order to solve these problems,Zhang Yuming et al.put forward double-sided arc welding(DSAW),as depicted in Fig.14[31].The main feature of DSAW is that two welding torches are placed on opposite sides of the workpiece,respectively,and simultaneously used to weld the workpiece.The experimental results shown that DSAW can not only increase weld penetration,reduce the temperature gradient of the weld in thickness direction,but also omit the backing weld and the corresponding back chipping,reduce the size of the groove and the corresponding filling metal.Therefore,

    DSAW has the advantages of high welding efficiency,small welding deformation,good joint quality and so on.

    Fig.13Electromagnetic force between two arcs

    Fig.14Double-sided arc welding system

    The common combinations of welding methods which are used to compose DSAW have four forms of TIGTIG,TIG-MIG,TIG-PAW and MIG-MIG.Among them,the combinations of TIG-TIG and TIG-PAW have more applications in industrial production.In general,when the workpiece is in downward welding position,TIG welding or PAW without filling wire is normally used on the back of the workpiece because MIG welding as the backing arc is difficult to get the stable droplet transfer on the back of the workpiece.When the workpiece is in vertical welding position,the combination of MIG-MIG can be used[32].

    According to the powered mode of the power supply,DSAW is classified into DSAW with one power supply and DSAW with two power supplies,as shown in Fig.14.The main features of DSAW with one power supply are that two arcs are powered by one power supply and cascaded in one welding circuit loop,and two welding torches are placed on both sides of the workpiece to implement welding symmetrically.In the process of welding,the welding current doesn’t flow through the surface of the workpiece again,but flows through the molten pool directly,which makes the welding current and two arcs distinctly concentrated by the electromagnetic interaction between two arcs,as shown in Fig.15,which greatly increases the weld penetration,the ratio of weld penetration to weld width,and the utilization rate of arc heat.For two power supplies type of DSAW,two arcs are powered by two different power supplies,respectively,and connected to two independent welding circuit loops,and two welding torches placed on the both sides of the workpiece carry out welding symmetrically or dislocation welding of one behind the other.Compared with DSAW with one power supply,DSAW with two power supplies has the stronger practicability in industrial applications due to the simpler system configuration and adjusting flexibility of welding parameters.However,DSAW has some limitation in industrial applications because of its mandatory

    requirement on the double side accessibility of the workpiece[32-33].

    Fig.15Welding current and induced magnetic field

    3Conclusion

    Gas shielded multi-arc welding can get the higher welding efficiency and better joint quality by means of the interaction between multiple arcs than conventional gas shielded single-arc welding,and has become one of the most popular welding methods to achieve the high efficiency welding.

    At present,the majority of gas shielded multi-arc welding technologies have not been widely and fully applied in industrial production.The main reasons are as follows:(1)The majority of gas shielded multi-arc welding is powered together by more than one power supply and thus needs to have an accurate coordination control system;(2)The fact that arc plasma has electromagnetic and thermodynamic properties makes the interaction between arcs very complex,which makes it difficult to get the stable arcs and control the droplet transfer accurately;(3)Optimizing welding parameters is difficult,because gas shielded multi-arc welding has many independent welding parameters and the interaction between arcs is also very complex;(4)Either a large size of welding torch or the combination of multiple normal welding torches is used in gas shielded multi-arc welding,which not only reduces the accessibility of welding position,but also needs the corresponding automatic auxiliary equipment(e.g.welding tractor,welding robot)to carry out welding together.

    In order to further promote the industrial application of gas shielded multi-arc welding,the corresponding welding system can be improved from the following several aspects:(1)How to boost the coordination control ability and integration of welding system;(2)How to increase the stability of arcs and the controllability of droplet transfer;(3)How to get the optimal welding parameters quickly.These are the important development directions of gas shielded multi-arc welding in the future.

    Gas shielded multi-arc welding is derived from conventional gas shielded single-arc welding.Compar-ed with some new types of high efficiency welding methods,such as laser welding,laser-arc hybrid welding,electron beam welding and friction stir welding,gas shielded multi-arc welding has the lower welding cost,more complete auxiliary facilities and stronger adaptability,so it has significant industrial application value and broad developm ent prospect.

    [1]Chen Q,Sun Z G.Development situation of arc welding technology[C].Beijing:InternationalForumforHighEfficiency Welding,2002.

    [2]Yin S Y.Research progress of high efficiency arc welding technology[J].Welding&Joining,2006(10):7-14.

    [3]Yin S Y.Foundation and application of gas shielded arc welding process[M].Beijing:China Machine Press,2012.

    [4]Shi Y,Li Y,Huang J K,et al.Research and development of high-efficiency MIG/MAG welding[J].Electric Welding Machine,2008,38(12):6-10.

    [5]Kobayashi K,Nishimura Y,Iijima T,et al.Practical application of high efficiency twin-arc TIG welding method(SEDAR-TIG)for PCLNG storage tank[J].Welding in the World,2004,48(7/8):35-39.

    [6]Chen J,Leng B,Yu H N.Status of research and development for multiple-wire welding technology[J].Welding Digest of Machinery Manufacturing,2015(3):24-29.

    [7]Zhang Y M,Jiang M,Lu W.Double electrodes GMAW improve heat input control[J].Welding Journal,2004,83(11):39-41.

    [8]Wang X Y,Yang X Q,Yang T,et al.Development of plasma-MIG hybrid arc welding technology[J].Welding&Joining,2012(8):26-29.

    [9]Kanemaru S,Sasaki T,Sato T,et al.Basic study on TIG-MIG hybrid welding process[J].Quarterly Journal of the Japan Welding Society,2012(30):29-34.

    [10]Song R L.Research and development of high performance welding arc[J].Electric Welding Machine,2013,43(3):1-5.

    [11]Wang S B.Research onphysicalcharacteristicsandweldingprocessof twin-electrode TIG welding method[D].Heilongjiang:Harbin Institute of Technology,2006.

    [12]Gu X L.Research on physical characteristics and welding process of twin-electrode TIG welding method[D].Heilongjiang:Harbin Institute of Technology,2007.

    [13]Cao M Q,Zou Z D,Zhang S S,et al.Present situation and development of twin-wire arc welding[J].Journal of Shandong University of Science and Technology(Natural Science),2008,27(2):88-92.

    [14]Zhang H B,Huang S S,Zhou Y Q,et al.Characteristics of twin arc GMAW with a common weld pool[J].Electric Welding Machine,2004,34(11):25-27.

    [15]Li X L,Huang S S,Wu K Y,et al.Present situation and developing trend of double wire pulsed MIG/MAG welding[J].Electric Welding Machine,2007,37(10):11-13.

    [16]Christoph K.TIME TWIN—Double-wirehighspeedwelding[C].TheAnnualMeetingofChineseMechanicalEngineeringSociety,2002.

    [17]Chen Y C,Li S N,Song Gang,et al.Modern efficient welding methods and their application[M].Beijing:China Machine Press,2015.

    [18]Ye D,Hua X,Wu Y.Arc interference behavior during twin wire gas metal arc welding process[J].Advances in Materials Science &Engineering,2013(312):83-87.

    [19]Ueyama T,Ohnawa T,Tanaka M,et al.Occurrence of arc interaction in tandem pulsed gas metal arc welding[J].Science&Technology of Welding&Joining,2007,12(6):523-529.

    [20]LI K H,CHEN J S,ZHANG Y M.Double-electrode GMAW process and control[J].Welding Journal,2007(86):231s-237s.

    [21]Zhu M.The Research on controlling of stability and metal transfer behavior in consumable DE-GMAW process[D].Gausu:Lanzhou University of Technology,2014.

    [22]Li K H,Zhang V M.Consumable double-electrode GMAW partⅡ:monitoring,modeling,and control[J].Welding Journal,2008,87(2):44s-50s.

    [23]Wang C C,Du B.R Investigation and application of Plasma-MIG/MAG hybrid welding technology[J].Welding&Joining,2009(12):62-64.

    [24]Que F H,Wang Z M.Research progress in the plasma-MIG welding[J].Electric welding machine,2013,43(3):28-32.

    [25]Bai Y,Gao H M,Wu L.State of study on arc characteristic during plasma-MIG welding process[J].Electric Welding Machine,2007,37(9):17-19.

    [26]Asai M S,Ogawa M T,Ishizaki M Y,et al.Application of plasma MIG hybrid welding to dissimilar joints between copper and steel [J].Welding in the World,2013,56(1/2):37-42.

    [27]Kanemaru S,Sasaki T,Sato T,et al.Study for TIG MIG hybrid welding process[J].Welding in the World,2014,58(1):11-18.

    [28]Yang T,Zhang S H,Gao H M,et al.Analysis of mechanism for TIG-MIG hybrid arc properties[J].Transactions of the China Welding Institution,2012,33(7):25-28.

    [29]Lou X F,Chen M A,Wu C S,et al.Humping and undercutting suppression mechanism for high speed TIG-MIG hybrid welding [J].Transactions of the China Welding Institution,2014,35(8):87-90.

    [30]Meng X,Qin G,Zhang Y,et al.High speed TIG MAG hybrid arc welding of mild steel plate[J].Journal of Materials Processing Technology,2014,214(11):2417-2424.

    [31]Zhang Y M,Zhang S B.Double-sided arc welding increases weld joint penetration[J].Welding Journal,1998,77(6):57-61.

    [32]Cui X M,Li L H,Zhang Y H.Analysis of double-sided arc welding technology and physical process[J].Journal of Beijing University of Aeronautics and Astronautics,2003(7):654-658.

    [33]Gao L,Tan Y F,Hao S Q,et al.Research situation on double side arc welding[J].Hot Working Technology,2012,41(3):157-159.

    TG444

    A

    1001-2303(2016)11-0009-12

    獻(xiàn)

    TANG Yingying,ZHU Zhiming,YANG Zhongyu,et al.High-efficiency Gas Shielded Multi-arc Welding Technology[J].電焊機(jī),2016,46(11):9-20.

    湯瑩瑩(1988—),女,河南開封人,在讀博士,主要從事焊接電弧物理及高效化復(fù)合焊接方面的研究工作。

    10.7512/j.issn.1001-2303.2016.11.02

    猜你喜歡
    電焊機(jī)高效化電弧
    故障電弧探測(cè)器與故障電弧保護(hù)裝置在工程中的應(yīng)用分析
    “雙減”背景下基于高中語文學(xué)科核心素養(yǎng)作業(yè)布置高效化的探索
    紅豆教育(2021年36期)2021-04-21 03:43:09
    高校低值易耗品管理高效化探討與研究
    增效肥料——推動(dòng)肥料高效化利用
    2219鋁合金激光電弧復(fù)合焊接及其溫度場(chǎng)的模擬
    地下密閉結(jié)構(gòu)內(nèi)高效化爆實(shí)驗(yàn)技術(shù)
    航空電氣系統(tǒng)中故障電弧的分析
    電子制作(2017年22期)2017-02-02 07:10:15
    2014年《電焊機(jī)》雜志專題討論
    電焊機(jī)(2014年3期)2014-03-12 06:51:44
    2014年《電焊機(jī)》雜志專題討論
    電焊機(jī)(2014年4期)2014-03-12 06:51:44
    2014年《電焊機(jī)》雜志專題討論
    電焊機(jī)(2014年2期)2014-03-12 06:50:24
    热99久久久久精品小说推荐| 中文字幕人妻熟人妻熟丝袜美| 国产无遮挡羞羞视频在线观看| 乱码一卡2卡4卡精品| a级片在线免费高清观看视频| 乱码一卡2卡4卡精品| 免费看不卡的av| 国语对白做爰xxxⅹ性视频网站| 欧美日韩成人在线一区二区| 一区在线观看完整版| 国产精品成人在线| 男女啪啪激烈高潮av片| 亚洲精品,欧美精品| 看非洲黑人一级黄片| 九九久久精品国产亚洲av麻豆| 少妇丰满av| 最近最新中文字幕免费大全7| 亚洲色图 男人天堂 中文字幕 | 国产精品麻豆人妻色哟哟久久| 考比视频在线观看| 不卡视频在线观看欧美| 免费观看在线日韩| 精品久久久久久久久亚洲| 久久久国产一区二区| 成人无遮挡网站| 性色av一级| 久热久热在线精品观看| 一个人免费看片子| 欧美xxxx性猛交bbbb| 亚洲国产成人一精品久久久| 亚洲五月色婷婷综合| 国产精品99久久99久久久不卡 | 少妇被粗大猛烈的视频| 欧美精品一区二区大全| 新久久久久国产一级毛片| 亚洲少妇的诱惑av| 精品亚洲成a人片在线观看| 三上悠亚av全集在线观看| 国产 精品1| 中文字幕av电影在线播放| 国产高清有码在线观看视频| 久久韩国三级中文字幕| 制服人妻中文乱码| 爱豆传媒免费全集在线观看| 日韩不卡一区二区三区视频在线| 日本av免费视频播放| 日韩av在线免费看完整版不卡| 午夜av观看不卡| 人成视频在线观看免费观看| 天天操日日干夜夜撸| 亚洲av日韩在线播放| 超色免费av| 精品一区二区免费观看| 免费高清在线观看日韩| 在线观看一区二区三区激情| 久久热精品热| 日韩伦理黄色片| 国产男女内射视频| av在线播放精品| 高清欧美精品videossex| 久久97久久精品| 一区二区三区免费毛片| 丝袜美足系列| 国产 精品1| 飞空精品影院首页| 天天影视国产精品| 少妇被粗大的猛进出69影院 | 亚洲欧美日韩卡通动漫| 国产成人aa在线观看| 中文字幕制服av| 国产精品不卡视频一区二区| 国产成人午夜福利电影在线观看| 黄色一级大片看看| 制服丝袜香蕉在线| 又大又黄又爽视频免费| 男女边吃奶边做爰视频| 黄色毛片三级朝国网站| 精品人妻熟女av久视频| 亚洲国产毛片av蜜桃av| 麻豆成人av视频| 国产成人精品无人区| 亚洲精品第二区| 亚洲国产精品一区二区三区在线| 久久av网站| 熟女av电影| 人人妻人人澡人人爽人人夜夜| 亚洲精华国产精华液的使用体验| 黑丝袜美女国产一区| 日韩av在线免费看完整版不卡| 日日撸夜夜添| 亚洲色图综合在线观看| 建设人人有责人人尽责人人享有的| 日韩欧美一区视频在线观看| 免费看不卡的av| 99精国产麻豆久久婷婷| 老司机影院毛片| 久久av网站| 国产成人精品无人区| 91精品三级在线观看| 日韩av免费高清视频| 国产高清国产精品国产三级| 国产免费现黄频在线看| 两个人免费观看高清视频| 欧美日韩亚洲高清精品| 亚洲美女搞黄在线观看| 精品亚洲成国产av| 大香蕉久久网| 久久99精品国语久久久| 久久精品国产自在天天线| 免费不卡的大黄色大毛片视频在线观看| 观看美女的网站| 日本猛色少妇xxxxx猛交久久| av视频免费观看在线观看| 丰满少妇做爰视频| 亚洲精品日韩av片在线观看| 91国产中文字幕| 男女边吃奶边做爰视频| 国语对白做爰xxxⅹ性视频网站| 高清欧美精品videossex| 亚洲四区av| 性色av一级| 亚洲精品乱码久久久v下载方式| 精品人妻在线不人妻| 免费看av在线观看网站| 丝袜在线中文字幕| 免费人成在线观看视频色| 少妇被粗大的猛进出69影院 | 一级毛片 在线播放| 亚洲激情五月婷婷啪啪| 三级国产精品欧美在线观看| 国产男女超爽视频在线观看| 成人二区视频| 日韩视频在线欧美| 国产精品人妻久久久久久| 五月开心婷婷网| 99视频精品全部免费 在线| 国产女主播在线喷水免费视频网站| 成人黄色视频免费在线看| 一级毛片 在线播放| 在线观看免费高清a一片| 亚洲精品成人av观看孕妇| tube8黄色片| 大香蕉久久网| 国产一区二区在线观看日韩| 视频中文字幕在线观看| 久久久久精品性色| 亚洲av成人精品一区久久| 人人妻人人澡人人爽人人夜夜| 亚洲精品美女久久av网站| 亚洲欧洲日产国产| 自拍欧美九色日韩亚洲蝌蚪91| 一边亲一边摸免费视频| 一区二区三区乱码不卡18| av.在线天堂| 18在线观看网站| 日韩av免费高清视频| 精品少妇内射三级| 成年人午夜在线观看视频| 欧美精品高潮呻吟av久久| 国产在线免费精品| av在线观看视频网站免费| 女人精品久久久久毛片| 亚洲精品美女久久av网站| 永久免费av网站大全| 看非洲黑人一级黄片| 视频中文字幕在线观看| 亚洲高清免费不卡视频| 日本黄色日本黄色录像| 国产免费又黄又爽又色| 精品一区二区三卡| 久久99精品国语久久久| 久久精品熟女亚洲av麻豆精品| 中文字幕久久专区| 两个人免费观看高清视频| 欧美xxⅹ黑人| 18禁在线无遮挡免费观看视频| 新久久久久国产一级毛片| a级毛色黄片| 国产精品不卡视频一区二区| 国产一区二区三区综合在线观看 | 亚洲欧美精品自产自拍| 欧美日本中文国产一区发布| 男的添女的下面高潮视频| 亚洲精品色激情综合| 亚洲成人手机| 妹子高潮喷水视频| 看十八女毛片水多多多| 日本wwww免费看| 色视频在线一区二区三区| 久久久久久久久久久丰满| 成年美女黄网站色视频大全免费 | 国产探花极品一区二区| 在线观看三级黄色| 国语对白做爰xxxⅹ性视频网站| 亚洲国产色片| 美女国产视频在线观看| 人体艺术视频欧美日本| 欧美+日韩+精品| 男的添女的下面高潮视频| 狂野欧美激情性xxxx在线观看| 国产日韩欧美视频二区| kizo精华| 国产成人精品无人区| 一本色道久久久久久精品综合| 一级毛片我不卡| 精品亚洲成a人片在线观看| 亚洲美女搞黄在线观看| 少妇 在线观看| 日韩精品免费视频一区二区三区 | 日日爽夜夜爽网站| 在线 av 中文字幕| 国产深夜福利视频在线观看| 亚洲第一区二区三区不卡| av又黄又爽大尺度在线免费看| 国产精品99久久99久久久不卡 | 肉色欧美久久久久久久蜜桃| 少妇的逼好多水| 最后的刺客免费高清国语| 久久精品国产亚洲av天美| 99精国产麻豆久久婷婷| 我的女老师完整版在线观看| 黄色视频在线播放观看不卡| 另类亚洲欧美激情| 国产免费一级a男人的天堂| 亚洲精品色激情综合| 精品久久久精品久久久| 狠狠精品人妻久久久久久综合| 伦理电影大哥的女人| 亚洲欧美成人综合另类久久久| 国产精品秋霞免费鲁丝片| 男女国产视频网站| 国产精品久久久久久av不卡| 婷婷成人精品国产| 久热这里只有精品99| 伦理电影大哥的女人| av播播在线观看一区| 亚洲综合色惰| 中文字幕最新亚洲高清| 最近2019中文字幕mv第一页| 自线自在国产av| 欧美变态另类bdsm刘玥| 最新的欧美精品一区二区| 人人妻人人添人人爽欧美一区卜| 欧美日韩亚洲高清精品| 国产av码专区亚洲av| 又大又黄又爽视频免费| 国产av国产精品国产| 国产精品蜜桃在线观看| 亚洲欧美成人精品一区二区| 毛片一级片免费看久久久久| 最近中文字幕高清免费大全6| 丰满饥渴人妻一区二区三| 亚洲三级黄色毛片| 老司机影院毛片| 日韩中文字幕视频在线看片| 亚洲精品久久午夜乱码| 精品亚洲乱码少妇综合久久| 欧美激情国产日韩精品一区| 欧美日韩视频精品一区| 蜜桃国产av成人99| 五月开心婷婷网| 各种免费的搞黄视频| 性色avwww在线观看| 又黄又爽又刺激的免费视频.| 伦理电影大哥的女人| 欧美日韩视频精品一区| 啦啦啦视频在线资源免费观看| 精品亚洲成a人片在线观看| 2022亚洲国产成人精品| 青青草视频在线视频观看| 下体分泌物呈黄色| 女的被弄到高潮叫床怎么办| 人妻 亚洲 视频| 国产永久视频网站| 欧美日韩在线观看h| 久久久久人妻精品一区果冻| 日韩一区二区三区影片| 99国产精品免费福利视频| 美女主播在线视频| 18禁在线播放成人免费| 高清毛片免费看| 寂寞人妻少妇视频99o| 亚洲国产av新网站| 国产免费视频播放在线视频| 亚洲人与动物交配视频| 久热这里只有精品99| 边亲边吃奶的免费视频| 久久午夜综合久久蜜桃| 国产深夜福利视频在线观看| 高清午夜精品一区二区三区| 99久久中文字幕三级久久日本| 久久久久久久精品精品| av黄色大香蕉| 一级,二级,三级黄色视频| 国产精品一区www在线观看| 久久久久网色| 精品人妻在线不人妻| 亚洲天堂av无毛| 2018国产大陆天天弄谢| 国产欧美另类精品又又久久亚洲欧美| 国产精品一二三区在线看| 久久精品国产亚洲av涩爱| 亚洲精品久久久久久婷婷小说| 伦理电影免费视频| 亚洲不卡免费看| 亚洲人成77777在线视频| 在线观看免费日韩欧美大片 | 中文字幕最新亚洲高清| 黄片无遮挡物在线观看| 日本午夜av视频| 午夜免费鲁丝| 国产69精品久久久久777片| 成年人免费黄色播放视频| 久久人人爽人人爽人人片va| 精品99又大又爽又粗少妇毛片| 欧美精品一区二区大全| 嫩草影院入口| a级片在线免费高清观看视频| 最新中文字幕久久久久| 国产 精品1| 日韩,欧美,国产一区二区三区| 男人操女人黄网站| 五月天丁香电影| 久久精品国产亚洲av涩爱| 人人妻人人澡人人看| 多毛熟女@视频| 免费日韩欧美在线观看| 亚洲精品一二三| 看非洲黑人一级黄片| 波野结衣二区三区在线| 精品亚洲成a人片在线观看| 99re6热这里在线精品视频| 人成视频在线观看免费观看| 久久影院123| 亚洲精品国产av蜜桃| 美女脱内裤让男人舔精品视频| 91aial.com中文字幕在线观看| 成人18禁高潮啪啪吃奶动态图 | 九色成人免费人妻av| 最近中文字幕2019免费版| 国产精品一区二区三区四区免费观看| 人妻夜夜爽99麻豆av| 国产日韩一区二区三区精品不卡 | 国产色婷婷99| 夜夜看夜夜爽夜夜摸| 亚洲综合色网址| 久久久久久久久久久久大奶| 久久久精品免费免费高清| 黄片无遮挡物在线观看| 久久国内精品自在自线图片| 丝瓜视频免费看黄片| 国产一区二区三区综合在线观看 | 午夜福利,免费看| 国产精品一国产av| 伦理电影大哥的女人| 亚洲av福利一区| av电影中文网址| 亚洲精品成人av观看孕妇| 国产av一区二区精品久久| 汤姆久久久久久久影院中文字幕| a级毛片免费高清观看在线播放| 久久99热6这里只有精品| 免费黄网站久久成人精品| 亚洲欧美清纯卡通| 99热全是精品| 日韩,欧美,国产一区二区三区| 亚洲欧洲国产日韩| 久久久久国产精品人妻一区二区| 国产在线免费精品| 国产日韩一区二区三区精品不卡 | www.av在线官网国产| 中文字幕最新亚洲高清| 精品久久久噜噜| 三级国产精品欧美在线观看| 国产成人av激情在线播放 | 亚洲av国产av综合av卡| 精品少妇内射三级| 欧美日本中文国产一区发布| 亚洲精品国产色婷婷电影| 欧美3d第一页| 久久久久久久久久成人| 日韩 亚洲 欧美在线| 在线精品无人区一区二区三| 在线观看三级黄色| 国产视频内射| 狂野欧美白嫩少妇大欣赏| 日本av手机在线免费观看| 亚洲高清免费不卡视频| 日韩一区二区三区影片| 午夜影院在线不卡| 人人妻人人澡人人爽人人夜夜| 国产精品一区二区在线不卡| 亚洲av成人精品一区久久| 亚洲国产av影院在线观看| 日本黄色片子视频| 一级毛片黄色毛片免费观看视频| 国产成人a∨麻豆精品| 秋霞在线观看毛片| 国产成人freesex在线| 超色免费av| 午夜福利视频精品| 成人午夜精彩视频在线观看| 如日韩欧美国产精品一区二区三区 | 国产免费福利视频在线观看| av在线播放精品| 人人妻人人爽人人添夜夜欢视频| 一本色道久久久久久精品综合| 亚洲精品国产av蜜桃| 成年美女黄网站色视频大全免费 | 久久久久久久国产电影| 亚洲精品自拍成人| 亚洲精品国产色婷婷电影| 看免费成人av毛片| 午夜福利视频在线观看免费| 欧美三级亚洲精品| 国产精品免费大片| 99久国产av精品国产电影| 国产成人午夜福利电影在线观看| 大陆偷拍与自拍| 成人漫画全彩无遮挡| 精品人妻一区二区三区麻豆| 久久99一区二区三区| 不卡视频在线观看欧美| 亚洲欧美成人精品一区二区| 国产熟女欧美一区二区| 欧美国产精品一级二级三级| 99热这里只有精品一区| 欧美日韩视频精品一区| 欧美丝袜亚洲另类| 视频在线观看一区二区三区| 春色校园在线视频观看| 大陆偷拍与自拍| 美女福利国产在线| 伦精品一区二区三区| 色哟哟·www| 日韩欧美一区视频在线观看| 久久久久视频综合| 国产高清三级在线| 精品一区二区免费观看| 亚洲精品第二区| 人人妻人人爽人人添夜夜欢视频| 欧美日韩精品成人综合77777| 国产黄色视频一区二区在线观看| 最近中文字幕2019免费版| 啦啦啦中文免费视频观看日本| 人妻系列 视频| 在线精品无人区一区二区三| 一级a做视频免费观看| 99久久精品国产国产毛片| 国产亚洲精品第一综合不卡 | 青青草视频在线视频观看| 国产精品久久久久久精品古装| 男女啪啪激烈高潮av片| 黄色视频在线播放观看不卡| 亚洲成人av在线免费| 久久99热这里只频精品6学生| 国产不卡av网站在线观看| 有码 亚洲区| 一级毛片aaaaaa免费看小| 一本—道久久a久久精品蜜桃钙片| 久久久精品区二区三区| 欧美精品人与动牲交sv欧美| 曰老女人黄片| 欧美日韩综合久久久久久| 国产精品女同一区二区软件| 亚洲三级黄色毛片| 成人国语在线视频| 欧美成人精品欧美一级黄| a级毛片在线看网站| 在线 av 中文字幕| 永久网站在线| 中文字幕精品免费在线观看视频 | 久久午夜综合久久蜜桃| 夫妻午夜视频| 亚洲国产成人一精品久久久| 这个男人来自地球电影免费观看 | 亚洲国产成人一精品久久久| 亚洲精品亚洲一区二区| 欧美xxxx性猛交bbbb| 欧美日本中文国产一区发布| 免费观看性生交大片5| 久热这里只有精品99| 亚洲欧美成人综合另类久久久| 久久久久久久国产电影| 少妇人妻 视频| 日日啪夜夜爽| 我的女老师完整版在线观看| 纯流量卡能插随身wifi吗| 亚洲精品,欧美精品| 丰满饥渴人妻一区二区三| 国产一区二区三区av在线| 韩国高清视频一区二区三区| 国产精品无大码| 久久精品久久久久久久性| 亚洲精品乱码久久久久久按摩| 亚洲国产最新在线播放| 少妇高潮的动态图| 国产精品免费大片| 丰满迷人的少妇在线观看| 九色亚洲精品在线播放| 夜夜看夜夜爽夜夜摸| 精品国产国语对白av| 女人久久www免费人成看片| 欧美少妇被猛烈插入视频| 18禁观看日本| 成人国产麻豆网| 中文字幕制服av| 亚洲精品视频女| 97精品久久久久久久久久精品| 91国产中文字幕| 如何舔出高潮| 26uuu在线亚洲综合色| 亚洲图色成人| 一区二区av电影网| 国产乱人偷精品视频| 国产欧美另类精品又又久久亚洲欧美| 国产亚洲精品第一综合不卡 | 国产精品国产三级专区第一集| 国产在线观看jvid| 国产成人精品在线电影| 久久精品国产a三级三级三级| 欧美人与性动交α欧美精品济南到| 激情视频va一区二区三区| 青草久久国产| 国产精品一区二区精品视频观看| 最近最新中文字幕大全免费视频| 777久久人妻少妇嫩草av网站| 日本a在线网址| 两性午夜刺激爽爽歪歪视频在线观看 | 操出白浆在线播放| 中文字幕av电影在线播放| 成年人免费黄色播放视频| 亚洲情色 制服丝袜| 亚洲国产欧美网| 日韩一区二区三区影片| 一级,二级,三级黄色视频| 黑人巨大精品欧美一区二区mp4| 亚洲精品中文字幕一二三四区 | 丝袜在线中文字幕| 操出白浆在线播放| 自线自在国产av| 国产欧美日韩综合在线一区二区| 亚洲成人免费电影在线观看| 国产成人影院久久av| 激情视频va一区二区三区| 麻豆av在线久日| 激情在线观看视频在线高清 | 日韩中文字幕视频在线看片| 精品一区二区三区视频在线观看免费 | 香蕉国产在线看| 丰满饥渴人妻一区二区三| 日本av免费视频播放| 飞空精品影院首页| 波多野结衣一区麻豆| 999精品在线视频| 人人妻人人澡人人看| 精品亚洲成a人片在线观看| 中文字幕色久视频| 精品视频人人做人人爽| 国产精品一区二区在线不卡| 日本黄色日本黄色录像| 色婷婷av一区二区三区视频| 午夜福利视频精品| 亚洲精品国产精品久久久不卡| 国产精品电影一区二区三区 | 丰满迷人的少妇在线观看| 热99国产精品久久久久久7| 免费观看av网站的网址| 欧美日韩亚洲国产一区二区在线观看 | 美女午夜性视频免费| 首页视频小说图片口味搜索| 无遮挡黄片免费观看| 中文字幕人妻熟女乱码| 妹子高潮喷水视频| 青草久久国产| www.自偷自拍.com| 亚洲成国产人片在线观看| videos熟女内射| 日本av免费视频播放| 一级毛片女人18水好多| 国产精品久久久久成人av| 日韩欧美三级三区| 男女高潮啪啪啪动态图| 亚洲精品一二三| 在线播放国产精品三级| 亚洲第一青青草原| 成人影院久久| 欧美成狂野欧美在线观看| 国产无遮挡羞羞视频在线观看| 青草久久国产| 飞空精品影院首页| 老司机午夜十八禁免费视频| 午夜福利视频在线观看免费| 午夜激情久久久久久久| 美女午夜性视频免费| 国产精品免费大片| 国产在线视频一区二区| 久久精品国产综合久久久| 黑丝袜美女国产一区| 国产精品久久久久久精品电影小说| 嫁个100分男人电影在线观看| 91九色精品人成在线观看| av有码第一页| 香蕉久久夜色| 国内毛片毛片毛片毛片毛片| 曰老女人黄片| 国产色视频综合| 日韩中文字幕欧美一区二区| 国产av又大| 日韩免费av在线播放| 大码成人一级视频| 成年动漫av网址| 三级毛片av免费| 亚洲国产中文字幕在线视频| 国产不卡av网站在线观看|