摘要
采用TIG焊焊接2.5 mm厚1Cr12Ni3MoVN马氏体不锈钢板材,研究焊接工艺参数对接头组织与力学性能的影响规律,并优化工艺参数。结果表明,焊接速度为0.95 mm/s时,随着焊接电流的增加,接头强度先增后减;焊接速度为2.33 mm/s时,随着电流持续增大,接头强度不断下降。当焊接电流为96 A、焊接速度为0.95mm/s、送丝速度为1 mm/s时,工艺参数所获接头力学性能最好,抗拉强度达988.8 MPa,与母材相当。硬度最高值位于焊缝处,约为611 HV;最低硬度处于热影响区的回火区,约为292 HV;母材硬度值约为321 HV。拉伸试样均在热影响区的回火区处断裂,试样断口形貌为浅韧窝形;焊缝组织为铸态板条马氏体,完全淬火区组织为粗大的板条马氏体组织,不完全淬火区组织为板条马氏体-铁素体组织,回火区组织为高温回火索氏体,其硬度比母材调质回火索氏体差。
The TIG welding was used to weld 2. 5 mm thick 1Cr12Ni3MoVN martensitic stainless steel plate,The influence of welding parameters on microstructure and mechanical properties of joints was studied and the welding process parameters were optimized. The results show that at the welding speed of 0. 95 mm / s,with the increase of the welding current,the strength of the joint is increased and then decreased. While at the welding speed of 2. 33 mm / s,the joint strength decreases with the increase of current. At the welding current of 96 A,the welding speed of 0. 95 mm / s,and the wire feeding speed of 1 mm / s,the tensile strength of the joints can be up to 988. 8 MPa,which is equivalent to the base metal. The highest hardness about 611 HV is located in the weld zone,the lowest hardness about 292 HV is in the tempering zone of HAZ. Tensile samples were fractured at the tempering zone of HAZ,the sample fracture are all of dimple surfaces. Weld microstructure for the configuration of the slab martensite,the microstructure of the complete quenching zone is a thick slab of martensite,the microstructure of incomplete quenched zone is lath martensite-ferrite element structure organization,the microstructure of tempering zone is high temperature tempering sorbite,its hardness lower than that quenched tempered sorbite of the base metal.
出处
《焊接》
北大核心
2016年第7期41-44,70,共4页
Welding & Joining
