Fe-Cr-C-V等離子堆焊層改善旋耕刀耐磨性和沖擊韌性

郝建軍，楊澤宇，馬璐萍，趙建國，劉敬春

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Fe-Cr-C-V等離子堆焊層改善旋耕刀耐磨性和沖擊韌性

郝建軍，楊澤宇，馬璐萍，趙建國，劉敬春

（河北農(nóng)業(yè)大學(xué)機電工程學(xué)院，保定 071001）

為解決農(nóng)機觸土部件耐磨性差、失效頻繁等問題，該文采用等離子堆焊技術(shù)在65Mn鋼基體上制備Fe-Cr-C-V堆焊層；利用金相顯微鏡、射線衍射儀分析了堆焊層的顯微組織和物相構(gòu)成；利用顯微硬度計、往復(fù)式摩擦磨損試驗機、自制土槽磨損試驗機、沖擊試驗機等設(shè)備測試了堆焊層的顯微硬度、耐磨性及沖擊韌性。結(jié)果表明，堆焊層與基體呈良好的冶金結(jié)合，F(xiàn)e-Cr-C-V堆焊層主要由-Fe、Cr7C3、M7C3([Fe,Cr]7C3)、Fe-Cr固溶體、VC等組成。與65Mn淬火鋼相比，F(xiàn)e-Cr-C-V堆焊層的維氏硬度提高了75%，磨損質(zhì)量降低了約67%。與Fe-Cr-C堆焊層相比，F(xiàn)e-Cr-C-V堆焊層維氏硬度提高了HV0.5100，沖擊韌性提高了21%。與常用的65Mn鏟尖相比，有Fe-Cr-C-V堆焊層的深松鏟鏟尖磨損質(zhì)量減少了78%，與常用60Si2Mn旋耕刀相比，有Fe-Cr-C-V堆焊層的旋耕刀平均磨損質(zhì)量減小約50%。該研究可為延長旋耕刀使用壽命提供參考。

復(fù)合涂層；顯微結(jié)構(gòu)；等離子；旋耕刀；Fe-Cr-C-V堆焊層；耐磨性；沖擊韌性

0 引 言

農(nóng)機觸土部件在使用過程中長期承受來自土壤中石英、長石、植物硅酸體及作物秸稈、雜草等的頻繁沖擊與磨損。石英、長石中的SiO2以及植物莖稈中的硅酸體都是硬度極高的磨料，顯微維氏硬度最高可達HV0.51 250[1]。旋耕刀、深松鏟、開溝器、犁鏵等農(nóng)機觸土部件在與這些硬質(zhì)顆粒接觸的過程中極易因磨粒磨損而失效。據(jù)不完全統(tǒng)計，80%以上的農(nóng)機觸土部件因磨粒磨損失效而報廢,農(nóng)機觸土部件的早期失效嚴重影響作業(yè)質(zhì)量和作業(yè)效率，提高作業(yè)成本[2-5]。同時，頻繁更換失效刀具還會增加勞動強度、延誤農(nóng)時。為了改善農(nóng)機觸土部件的力學(xué)性能，很多國內(nèi)外學(xué)者借助氬弧熔覆、激光熔覆、火焰噴焊、感應(yīng)熔覆等手段，在觸土部件表面制備Fe基、Ni基、Co基等自熔性合金粉末涂層[6-9]，如郝建軍等[10]利用氬弧熔覆技術(shù)在廉價的碳鋼表面原位合成了TiC/Ni基復(fù)合材料涂層，熔覆層成型良好，試驗表明可用于農(nóng)機耐磨件的制造與再制造，并具有較好的經(jīng)濟效益。郝建軍等[11]利用氧乙炔火焰噴焊技術(shù)在鞭式滅茬刀具上制備了Ni-WC噴焊層，結(jié)果表明WC能夠?qū)︽嚮辖甬a(chǎn)生彌散強化、晶界強化和固溶強化的作用，提高噴焊層耐磨性。屈平等[12-13]利用等離子熔覆技術(shù)在犁鏵表面制備了Ti（C,N）-WC復(fù)合陶瓷涂層，熔覆后的犁鏵耐磨性明顯提高，使用壽命延長。趙建國等[14]利用反應(yīng)氮弧熔覆技術(shù)在旋耕刀上成功制備了TiCN/Fe金屬陶瓷涂層，涂層成型良好，顯微硬度達HV0.51 089，田間試驗表明相同條件下，涂層旋耕刀的磨損量僅為65Mn旋耕刀的1/2，耐磨性優(yōu)良。趙建國等[15]采用火焰噴焊技術(shù)在深松鏟鏟尖上制備了鐵基合金涂層，并利用噴焊后余溫對其進行了淬火處理，結(jié)果表明噴焊余溫淬火使涂層組織得到細化，提高了涂層耐磨性。張旭等[16]針對滅茬刀耐磨性不足，報廢、更換頻繁的問題，采用氧乙炔火焰噴焊技術(shù)在滅茬刀上制備了Fe6涂層，結(jié)果顯示噴焊Fe6涂層的滅茬刀硬度和耐磨性顯著提高，使用壽命得到有效延長。王海淞等[17]利用氬弧熔覆技術(shù)在淬火后的65Mn深松鏟鏟尖上制備了TiC顆粒增強鎳基復(fù)合涂層，TiC顆粒呈彌散分布，熔覆后的深松鏟具有較好的耐磨性。Satit等[18]采用高速氧燃料噴涂方法在旋耕刀表面制備了WC/Co復(fù)合涂層，田間試驗結(jié)果表明，噴涂WC/Co耐磨層的旋耕刀延壽效果明顯。Amardeep Singh Kang等[19]利用熱噴涂技術(shù)在旋耕刀表面分別制備了WC-Co-Cr、Cr3C2NiCr、Stellite-21涂層，田間試驗結(jié)果表明，噴涂WC-Co-Cr、Cr3C2NiCr、Stellite-21三種涂層的旋耕刀磨損質(zhì)量較原刀具下降明顯，耐磨性顯著提高。由此可見，上述方法均在不同程度上提高了農(nóng)機觸土部件的耐磨性和使用壽命，但上述方法多存在設(shè)備昂貴、工藝過程復(fù)雜或者原材料Ni、Co、WC、TiC成本高等不足。Fe-Cr-C系涂層具有成本低、硬度高、耐磨性好等優(yōu)點，已被廣泛應(yīng)用于材料表面強化領(lǐng)域，但涂層韌性差，易產(chǎn)生裂紋和脆斷現(xiàn)象[20-22]。Fe-Cr-C系合金中適量加入V元素，可達到細化晶粒和沉淀強化的作用[23]，有望改善涂層的綜合力學(xué)性能。為此，本文針對農(nóng)機觸土部件的使用特點，嘗試運用等離子堆焊技術(shù)在65Mn鋼表面制備耐沖擊、耐磨損的Fe-Cr-C-V堆焊層，以期為農(nóng)機觸土刀具的強化提供有效手段。

1 材料與方法

1.1 試驗材料

試驗基材為未經(jīng)熱處理的65Mn鋼板（120 mm′50 mm′12 mm），試驗所用粉末為粒徑100～150m的FJ-19（上海鑄宇材料科技有限公司）和粒徑為200～300m的FeV80釩鐵粉（南宮市鑫盾合金焊材噴涂有限公司），化學(xué)成分見表1。

表1 試驗材料化學(xué)成分

1.2 試驗方法

1.2.1 堆焊層制備

對65Mn試件表面進行噴砂處理（噴砂壓力0.7 MPa，G16鋼砂，噴砂角75°，噴砂距離100 mm），直至表面出現(xiàn)金屬光澤，然后用濃度為99.5%的丙酮溶液清洗試件，并用風(fēng)機吹干。用FA2204B型電子分析天平按1∶7（前期大量試驗及相關(guān)測試分析證明，V元素質(zhì)量比小于5%時V固溶于基體，不會形成VC，而超過15%時堆焊合金硬度和耐磨性呈下降趨勢，V質(zhì)量比為10%的Fe-Cr-C-V堆焊層顯微形貌和綜合性能良好）的比例稱取FeV80和FJ-19粉，然后采用DQM型行星式球磨機進行球磨混粉（轉(zhuǎn)速90 r/min，球磨時間8 h，球料比5∶1，干磨）。利用DML-V02BD型等離子堆焊機采用相同的堆焊工藝參數(shù)在65Mn鋼基體上分別制備厚度為（1.5±0.2）mm的Fe-Cr-C系和Fe-Cr-C-V系堆焊層。堆焊工藝參數(shù)為：堆焊電流55 A，送粉量25 g/min，離子氣1.5 L/min，送粉氣2.5 L/min，保護氣0.5 L/min，堆焊速度16 cm/min，堆焊角度為90°±8°，堆焊距離5～8 mm。

1.2.2 堆焊層性能表征

采用SG9000型數(shù)控電火花線切割機分別對普通65Mn鋼試件、Fe-Cr-C系堆焊試件和Fe-Cr-C-V系堆焊試件進行線切割，分別制備用于顯微分析的試件（15 mm′15 mm′12 mm）和用于耐磨性測試的試件（25 mm′25 mm′12 mm），耐磨性測試試件每種切取3個，測試結(jié)果取平均值。采用徠卡DM4000M型金相顯微鏡觀察堆焊層微觀組織形貌；采用德國布魯克生產(chǎn)的TECBRUKER D2PHASER型射線衍射儀對堆焊層進行物相分析，（衍射角度范圍10°<2<90°，步進角度0.02°）；采用上海恒一精密儀器有限公司生產(chǎn)的MH-6型顯微維氏硬度儀測試試件的顯微維氏硬度（加載載荷500 gf，加載時間10 s），每組硬度測試6次，結(jié)果取平均值。

1.2.3 堆焊層沖擊韌性試驗

采用JB-300B型沖擊試驗機測試Fe-Cr-C系和Fe-Cr-C-V系堆焊層的沖擊韌性。按GB229-84和GB/ T1817—2007的有關(guān)要求將堆焊層制備成55 mm′10 mm′5 mm的V形缺口試件進行沖擊韌性測試。每種成分堆焊層各制備3個沖擊韌性測試試件，測試結(jié)果取平均值。

1.2.4 堆焊層耐磨性測試

采用HSR-2M型往復(fù)式摩擦磨損試驗機測試堆焊層的耐磨性，加載載荷50 N，轉(zhuǎn)速300 r/min，往復(fù)距離 4 mm，磨頭為直徑4 mm的SiN陶瓷球，每隔1 h測量1次磨損質(zhì)量，總磨損時間為5 h，每測試1個試件更換1次SiN陶瓷球，每個試件重復(fù)3次測試。利用FA2204B型電子分析天平稱質(zhì)量并計算磨損質(zhì)量，稱質(zhì)量前用SB-5200D型超聲波清洗儀清洗試件后再用風(fēng)機吹干。

再準(zhǔn)備2組65Mn材質(zhì)的深松鏟鏟尖（110 mm×70 mm× 8 mm），其中1組不做表面強化處理，另1組在易磨損部位制備Fe-Cr-C-V堆焊層。采用自制的土槽磨損試驗機（專利號：ZL-201520998176.0,ZL201521030760.3）模擬深松鏟實際工作過程，通過測試深松鏟鏟尖的磨損質(zhì)量評價耐磨性。測試所用土壤為粒徑200目、含水率15%的沙壤土，試驗機轉(zhuǎn)速45 r/min，試驗時間12 h，磨損前后，用清水將試件沖洗干凈，吹干后稱質(zhì)量。

2 結(jié)果與分析

2.1 涂層橫截面形貌

圖1a和圖1b分別為Fe-Cr-C系和Fe-Cr-C-V系合金堆焊層橫截面顯微組織形貌。由圖1可見，堆焊層具有較低的稀釋率，沒有出現(xiàn)明顯的氣孔及夾雜物，堆焊區(qū)、結(jié)合區(qū)、基體區(qū)分布較為明顯，在結(jié)合區(qū)可以看到堆焊層與基體相互滲透，呈現(xiàn)良好的冶金結(jié)合。Fe-Cr-C系結(jié)合區(qū)為很窄的一條暗色“帶狀”區(qū)域[21]，是由基體與堆焊層相互滲透形成的。而Fe-Cr-C-V系結(jié)合區(qū)為白亮色“帶狀”區(qū)域，呈現(xiàn)如區(qū)域所示的平面晶形態(tài)[21,24]，這是由于基體的稀釋作用，結(jié)合區(qū)Cr/C比降低，共晶點左移，向亞共晶組織轉(zhuǎn)變造成的。

圖1 堆焊層橫截面形貌(65Mn基體)

2.2 涂層顯微組織

圖2a、圖2b為Fe-Cr-C系合金堆焊層微區(qū)的細微形貌，未添加釩鐵的Fe-Cr-C堆焊層硬質(zhì)相呈空心六邊狀、針葉狀及其他不規(guī)則形狀，分布雜亂，且硬質(zhì)相較為粗大（其中，針葉狀硬質(zhì)相可達200m）。在空心六邊形心部存在單個或多個孔洞，孔洞內(nèi)部充滿基體金屬，金屬組織為奧氏體或奧氏體轉(zhuǎn)變產(chǎn)物[25]。圖2c、圖2d為Fe-Cr-C-V系堆焊層顯微組織形貌，硬質(zhì)相形貌得到改善，除原有的針葉狀和六邊形初生碳化物外，還出現(xiàn)了彌散分布的球狀碳化物及柱狀晶、等軸晶等組織。與圖2a、2b相比，硬質(zhì)相尺寸明顯減小，約為10～20m。Fe-Cr-C-V系涂層結(jié)合區(qū)附近靠近激冷層處出現(xiàn)胞狀晶和柱狀晶垂直于界面，定向生長[24,26-27]。定向生長的硬質(zhì)相為板條狀晶體，其在不同方向上的硬度差異很大，由測試結(jié)果顯示，板條橫截面上的顯微硬度為HV0.51 700～1 900，而縱截面的顯微硬度為HV0.51 300～1 500，晶體的定向生長使大部分抗磨面為板條狀晶體的橫截面，有利于提高堆焊層整體硬度和抗磨性。

圖2 合金堆焊層顯微結(jié)構(gòu)（65Mn基體）

2.3 涂層物相

圖3為Fe-Cr-C系和Fe-Cr-C-V系堆焊層的XRD物相分析結(jié)果。由圖3a可以看到Fe-Cr-C合金堆焊層主要由-Fe、Fe-Cr固溶體、M7C3([Fe,Cr]7C3)、Cr7C3組成，其中M7C3和Cr7C3是主要硬質(zhì)相。Cr7C3的顯微維氏硬度可達HV0.51 700，其晶體屬于斜方晶系，而M7C3顯微維氏硬度可達HV0.51 900，是鉻原子溶入Fe7C3后形成的穩(wěn)定化合物[28-31]。圖3b為Fe-Cr-C-V系堆焊層物相分析結(jié)果，衍射結(jié)果表明，堆焊層中出現(xiàn)了VC新相，且M7C3和固溶體的峰值有所增加。文獻[32]研究表明，V是強碳化物形成元素，主要存在于M7C3型碳化物中。由Bramfitt理論，C優(yōu)先與V形成高熔點立方晶結(jié)構(gòu)的VC[33]，VC與M7C3的錯配度為8.6%，凝固過程中可以作為M7C3型碳化物的異質(zhì)形核基底，細化共晶組織。

圖3 堆焊層XRD衍射圖譜

2.4 顯微硬度分析

圖4為65Mn鋼（840 ℃淬火、400 ℃回火處理）、Fe-Cr-C系和Fe-Cr-C-V系堆焊試件的截面顯微硬度分布。由圖4可見：65Mn鋼的維氏硬度平均值為HV0.5460，F(xiàn)e-Cr-C系合金1 mm厚堆焊層的維氏硬度平均值為HV0.5710，而Fe-Cr-C-V系合金1 mm厚堆焊層的維氏硬度平均值為HV0.5810，比Fe-Cr-C系合金涂層硬度約增加了HV0.5100，相比于普通熱處理65Mn鋼，維氏硬度提升了75%。Fe-Cr-C-V系涂層比Fe-Cr-C系涂層具有更高的硬度，且在涂層橫截面上硬度較均勻，在垂直于涂層表面的方向上硬度沒有明顯的梯度變化，硬度均勻一致，這說明硬質(zhì)相在涂層內(nèi)是彌散分布的。新生相VC是硬度極高的硬質(zhì)相[34-35]，顯微維氏硬度達HV0.52 800，VC的釘扎作用提高了涂層的整體硬度。

圖4 試件橫截面硬度分布

2.5 耐磨性分析

圖5為65Mn熱處理試件、Fe-Cr-C系堆焊試件及Fe-Cr-C-V系堆焊試件在HSR-2M型往復(fù)式摩擦磨損試驗機上測試的磨損質(zhì)量變化。由圖5可知，65Mn試件的磨損速率約為6 mg/h，磨損速度快、磨損過程極不穩(wěn)定，4 h以后進入急劇磨損階段，而Fe-Cr-C-V系堆焊層的磨損速率約為2 mg/h，總體來說Fe-Cr-C-V系合金層的磨損質(zhì)量相比65Mn鋼降低了約67%。Fe-Cr-C系和Fe-Cr-C-V系堆焊層耐磨性較好，但Fe-Cr-C-V系堆焊層的磨損質(zhì)量更小，磨損曲線更加穩(wěn)定，具有更加優(yōu)良的耐磨性能。這是因為65Mn基體上彌散分布的碳化物硬質(zhì)相起到了抗磨骨架的作用，而Fe基體中的韌性相又對碳化物粘結(jié)固化，二者相互作用共同提高了涂層的耐磨性能。

圖5 試件磨損質(zhì)量對比

圖6所示為土槽試驗對比實樣的磨損形貌。由圖6可見，無堆焊層的65Mn試件磨損嚴重，端部有嚴重擦傷、犁溝明顯（磨損質(zhì)量為54.6 g）；而端部制備Fe-Cr-C-V堆焊層的涂層試件磨損表面光潔，未見嚴重的磨痕和堆焊層剝落現(xiàn)象（磨損質(zhì)量為12 g），與無涂層鏟尖相比，摩損質(zhì)量減少了78%。由此可見，F(xiàn)e-Cr-C-V堆焊層具有更加優(yōu)良的耐磨性能。

圖6 土槽磨損試驗后深松鏟鏟尖形貌

2.6 沖擊韌性分析

圖7為Fe-Cr-C系和Fe-Cr-C-V系堆焊合金沖擊韌性測試結(jié)果，F(xiàn)e-Cr-C系堆焊試件的平均沖擊韌性為 6.2 J/cm2，而Fe-Cr-C-V系堆焊合金的平均沖擊韌性為 7.5 J/cm2，與Fe-Cr-C系合金相比，F(xiàn)e-Cr-C-V系合金的沖擊韌性提高了21%。堆焊合金沖擊韌性的提高主要得益于碳化物形貌的改善，F(xiàn)e-Cr-C系合金中碳化物呈網(wǎng)狀聚集，對基體的割裂作用尤為嚴重，在宏觀上表現(xiàn)為涂層的開裂和剝落[36]；而Fe-Cr-C-V系堆焊合金冷凝時析出細小的二次VC，有效消耗熔池中的C原子，避免初生碳化物呈網(wǎng)狀聚集、長大。

圖7 沖擊韌性測試結(jié)果

3 田間試驗與結(jié)果分析

取60把60Si2Mn材質(zhì)的245旋耕刀（840 ℃淬火、400 ℃回火），其中30把采用本文試驗方法在其刃部制備1.5 mm厚的堆焊層。將60把旋耕刀洗凈、稱質(zhì)量后交錯安裝在1GKN-220型旋耕機上，在石家莊市藁城區(qū)綠之寶家庭農(nóng)場進行田間試驗。作業(yè)現(xiàn)場如圖8所示，總作業(yè)面積23.3 hm2，機組前進速度4～5 km/h，土壤性質(zhì)為砂壤土，含水率18%。

圖8 田間試驗

圖9為旋耕刀田間磨損宏觀形貌對比，由圖9可知，未堆焊Fe-Cr-C-V涂層的旋耕刀，在正切刃和側(cè)切刃相交區(qū)域出現(xiàn)明顯磨痕，且刀刃鈍化嚴重，而有堆焊層的旋耕刀刃部堆焊層保留較為完好，未出現(xiàn)嚴重磨損及涂層剝落。對所有刀具洗凈吹干后稱質(zhì)量，普通刀平均磨損質(zhì)量為60 g，涂層刀平均磨損質(zhì)量為32 g，與無涂層鏟尖相比，摩損質(zhì)量減少了50%。在田間試驗過程中涂層刀具有較好的耐磨性。

圖9 田間試驗后刀具形貌

4 結(jié) 論

1）Fe-Cr-C-V等離子堆焊層與基體呈良好的冶金結(jié)合，堆焊層無氣孔、夾渣等缺陷。堆焊層主要由M7C3（[Fe,Cr]7C3）、Cr7C3、-Fe、Fe-Cr、VC等物相組成。

2）與Fe-Cr-C堆焊層相比，F(xiàn)e-Cr-C-V堆焊層顯微組織更加細化，硬度增加，磨損量降低，且具有更加優(yōu)良的沖擊韌性。硬質(zhì)相的細化、彌散分布以及VC新相的出現(xiàn)是堆焊層強化的主要原因，而碳化物形貌的改善改良了涂層的沖擊韌性。Fe-Cr-C堆焊層的平均硬度為HV0.5710，沖擊韌度6.2 J/cm2；Fe-Cr-C-V堆焊層的平均硬HV0.5810，沖擊韌度7.5 J/cm2，F(xiàn)e-Cr-C-V堆焊層具有更加優(yōu)良的耐磨性能和沖擊韌性。

與常用65Mn、60Si2Mn材質(zhì)的旋耕刀相比，有Fe-Cr-C-V堆焊層的旋耕刀耐磨性良好，綜合力學(xué)性能優(yōu)良，可通過堆焊Fe-Cr-C-V涂層提高旋耕刀耐磨性。

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Fe-Cr-C-V plasma surfacing layer improving wear resistance and impact toughness of rotary blade

Hao Jianjun, Yang Zeyu, Ma Luping, Zhao Jianguo, Liu Jingchun

(071001,)

In order to solve the problems of poor wear resistance and frequent failure of agricultural machinery contact soil components, Fe-Cr-C-V plasma surfacing layer was prepared on 65Mn steel matrix by plasma surfacing welding technology. Microstructure and phase composition of surfacing layer were analyzed by means of metallographic microscope and-ray diffraction. Microhardness, wear resistance and impact toughness of surfacing layer were analyzed by means of microhardness tester, reciprocating friction and wear tester, self-made soil-bin wear tester and impact testing machine. The results showed that the cross-section of the surfacing welding specimen showed surfacing region, bonding region and substrate region, the substrate and coating diffused with each other, showing good metallurgical bonding, the coating dilution rate was low, and there were no defects such as porosity and slag inclusion. Fe-Cr-C-V series surfacing layer was mainly composed of-Fe,Cr7C3,M7C3([Fe,Cr]7C3), Fe-Cr solid solution, VC, etc. The microstructure and hard phase morphology of Fe-Cr-C-V surfacing layer were improved. In addition to the original coniferous and hexagonal primary carbides, the dispersed spherical carbides, columnar crystals also appeared. Composed with 65Mn hardened steel, the Vickers hardness of Fe-Cr-C-V series alloy layer was improved by 75% and the wear quality was reduced by about 67%. Compared with Fe-Cr-C series alloy, Fe-Cr-C-V series alloy had finer microstructure, higher hardness, lower wear and better impact toughness. Fe-Cr-C-V surfacing layer had smaller wear quality, more stable wear curve and better wear resistance, this is because that the carbide hard phase dispersed on 65Mn matrix play the role of anti-wear skeleton, while the toughness phase in Fe matrix bonds and solidified the carbide, and the 2 interactions jointly improved the wear resistance of the coating. The refinement and dispersion of hard phase and the appearance of new VC phase were the main reasons for the coating strengthening, while the carbide morphology improved the impact toughness of the coating. The average hardness and impact toughness of Fe-Cr-C alloy were HV0.5710 and 6.2 J/cm2respectively. The average hardness of Fe-Cr-C-V series alloy layer was HV0.5810, and the impact toughness was 7.5 J/cm2. Fe-Cr-C-V series alloy layer had better wear resistance and impact toughness. Compared with the commonly used 65Mn subsoiler tip, the wear quality of subsoiler tip with surfacing layer was reduced by 78%. Field experiments showed that the average wear quality of the rotary blade with surfacing layer was reduced by about 50% compared with the conventional 60Si2Mn rotary blade without surfacing layer. For the rotary blades without Fe-Cr-C-V surfacing layer, there were obvious wear marks in the intersection area between the cutting edge and the side cutting edge, and the blade passivation was serious, while the surfacing layer on the blade of the rotary blade with surfacing layer remained relatively intact, without serious wear and coating peeling. The average wear quality of rotary blade with surfacing layer was 32 g, and that of ordinary rotary blade without surfacing layer was 60 g. The hardness phase of Fe-Cr-C-V coating studied was uniformly distributed and there was no obvious hardness gradient, which has important reference value for extending the life of soil contact parts of agricultural machinery. In addition, plasma surfacing welding technology was used to prepare Fe-Cr-C-V series wear-resisting coating on the surface of the soil contact parts of agricultural machinery, which has low cost, high efficiency, flexible and convenient technology and high application and promotion value. Compared with the commonly used rotary blades with 65Mn and 60Si2Mn materials, the rotary blades with Fe-Cr-C-V surfacing layer has good wear resistance and excellent comprehensive mechanical properties.

composite coatings; microstructure; plasmas; rotary blade; Fe-Cr-C-V surfacing layer; wear resistance; impact toughness

郝建軍，楊澤宇，馬璐萍，趙建國，劉敬春. Fe-Cr-C-V等離子堆焊層改善旋耕刀耐磨性和沖擊韌性[J]. 農(nóng)業(yè)工程學(xué)報，2019，35(3)：24－30. doi：10.11975/j.issn.1002-6819.2019.03.004 http://www.tcsae.org

Hao Jianjun, Yang Zeyu, Ma Luping, Zhao Jianguo, Liu Jingchun. Fe-Cr-C-V plasma surfacing layer improving wear resistance and impact toughness of rotary blade[J]. Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 2019, 35(3): 24－30. (in Chinese with English abstract) doi：10.11975/j.issn.1002-6819.2019.03.004 http://www.tcsae.org

2018-10-30

2019-01-09

國家重點研發(fā)計劃（2017YFD0300907）

郝建軍，博士，教授，博士生導(dǎo)師，主要從事農(nóng)業(yè)機械裝備設(shè)計與制造相關(guān)研究。Email：hjjpaper@163.com

10.11975/j.issn.1002-6819.2019.03.004

TG174.4

A

1002-6819(2019)-03-0024-07