瞬时液相扩散焊双温和三温工艺下T91钢接头的显微组织与力学性能
|
摘要
分别采用瞬时液相扩散焊双温及三温工艺对T91钢管进行了焊接,采用扫描电镜、能谱仪、电子万能力学试验机、摆锤冲击试验机及弯曲试验机等研究了接头的显微组织、元素分布、力学性能等。结果表明:2种工艺下T91钢接头的成形质量均较好;双温工艺下接头焊缝近似直线,接头有钎焊特征,焊缝处镍元素富集导致黑色脆性相的生成;三温连接接头焊缝呈曲线状,镍元素得到均匀化扩散,接头的组织、成分与母材的相似;三温工艺下接头的抗拉强度为660MPa,冲击功为25.7J,三点弯曲180°而不裂,力学性能比双温工艺下的有显著提高;双温工艺下接头的断裂形式为韧-脆性混合断裂,三温工艺下的为典型的韧性断裂。
T91steel tube was bonded by transient liquid-phase bonding under two and three-step heating process,respectively.The microstructure,element distribution and mechanical properties of the joints were investigated by scanning electron microscopy,energy dispersive spectrometer,electronic universal testing machine,Charpy test device and bending testing machine.The results show that T91 steel joint had good formation quality under two heating processes.The joint under two-step heating process had the approximate line weld and brazing characteristics,and the Ni enrichment in weld resulted in the formation of black brittle phase.The weld of joint under three-step heating process was curved;Ni element distributed evenly;the microstructure and composition of the joint were the same with those of the base metal;the tensile strength was 660 MPa,the impact energy was25.7Jand the joint did not cracked during bending 180°;the mechanical properties were improved compared with that under two-step heating process.The fracture mode of the joint under two-step heating process was ductilebrittle mixed fracture,and the fracture mode under three-step heating process was typical ductile fracture.
T91steel tube was bonded by transient liquid-phase bonding under two and three-step heating process,respectively.The microstructure,element distribution and mechanical properties of the joints were investigated by scanning electron microscopy,energy dispersive spectrometer,electronic universal testing machine,Charpy test device and bending testing machine.The results show that T91 steel joint had good formation quality under two heating processes.The joint under two-step heating process had the approximate line weld and brazing characteristics,and the Ni enrichment in weld resulted in the formation of black brittle phase.The weld of joint under three-step heating process was curved;Ni element distributed evenly;the microstructure and composition of the joint were the same with those of the base metal;the tensile strength was 660 MPa,the impact energy was25.7Jand the joint did not cracked during bending 180°;the mechanical properties were improved compared with that under two-step heating process.The fracture mode of the joint under two-step heating process was ductilebrittle mixed fracture,and the fracture mode under three-step heating process was typical ductile fracture.
引文
[1]王卫泽,王钥,朱月梅,等.我国P91/T91钢生产及其性能的现状与进展[J].机械工程材料,2010,34(6):6-9.
[2]常铁军,龚正春,李子峰,等.T91钢TIG+MIG焊接接头性能及组织[J].焊接学报,2005,26(12):59-61.
[3]王娟,李亚江,周冰.T91钢焊缝及热影响区显微组织图象分析[J].材料科学与工艺,2001,9(1):95-99.
[4]杨新宇,姜勇,高巍,等.焊接顺序及热处理对T91/12Cr1MoV异质接头残余应力影响的数值分析[J].电焊机,2016,46(4):17-21.
[5] DUVALL D S.TLP bonding:A new method for joining heat resistant alloys[J].Welding Journal,1974,53:203-214.
[6]陈思杰,葛利玲,井晓天.等温温度对T91钢TLP双温连接接头组织性能的影响[J].焊接学报,2009,30(4):57-60.
[7]陈思杰,井晓天,李辛庚.工艺参数对T91钢管TLP连接组织和性能的影响[J].材料科学与工艺,2006,14(4):341-344.
[8]王非森,陈思杰,高增,等.T91钢管TLP与TIG+MIG焊接接头组织与性能[J].热加工工艺,2009,38(21):142-143.
[9] SHIRZADI A A,WALLACH E R.Analytical modelling of transient liquid phase(TLP)diffusion bonding when a temperature gradient is imposed[J].Acta Materialia,1999,47(13):3551-3560.
[10]陈思杰,井晓天,李辛庚.瞬时液相扩散连接的双温工艺模型[J].焊接学报,2005,26(4):69-72.
[11]张远辉,王非森,张安民.瞬时液相扩散连接工艺参数及应用研究进展[J].热加工工艺,2010,39(9):163-166.
[12]唐恒娟,陈思杰.异种耐热钢瞬时液相扩散连接界面形态与形成机理[J].焊接学报,2012,33(3):101-104.
[2]常铁军,龚正春,李子峰,等.T91钢TIG+MIG焊接接头性能及组织[J].焊接学报,2005,26(12):59-61.
[3]王娟,李亚江,周冰.T91钢焊缝及热影响区显微组织图象分析[J].材料科学与工艺,2001,9(1):95-99.
[4]杨新宇,姜勇,高巍,等.焊接顺序及热处理对T91/12Cr1MoV异质接头残余应力影响的数值分析[J].电焊机,2016,46(4):17-21.
[5] DUVALL D S.TLP bonding:A new method for joining heat resistant alloys[J].Welding Journal,1974,53:203-214.
[6]陈思杰,葛利玲,井晓天.等温温度对T91钢TLP双温连接接头组织性能的影响[J].焊接学报,2009,30(4):57-60.
[7]陈思杰,井晓天,李辛庚.工艺参数对T91钢管TLP连接组织和性能的影响[J].材料科学与工艺,2006,14(4):341-344.
[8]王非森,陈思杰,高增,等.T91钢管TLP与TIG+MIG焊接接头组织与性能[J].热加工工艺,2009,38(21):142-143.
[9] SHIRZADI A A,WALLACH E R.Analytical modelling of transient liquid phase(TLP)diffusion bonding when a temperature gradient is imposed[J].Acta Materialia,1999,47(13):3551-3560.
[10]陈思杰,井晓天,李辛庚.瞬时液相扩散连接的双温工艺模型[J].焊接学报,2005,26(4):69-72.
[11]张远辉,王非森,张安民.瞬时液相扩散连接工艺参数及应用研究进展[J].热加工工艺,2010,39(9):163-166.
[12]唐恒娟,陈思杰.异种耐热钢瞬时液相扩散连接界面形态与形成机理[J].焊接学报,2012,33(3):101-104.