P92钢焊接接头显微组织与性能的研究

Study on microstructure and mechanical properties of welded joint of P92 steel

采用合适的焊接工艺对P92钢进行焊接,利用硬度计、金相显微镜和万能拉伸试验机对其焊接接头的硬度、微观组织和常温拉伸力学性能进行分析。结果表明:P92钢焊接后焊缝区组织为铁素体+马氏体+碳化物,热影响区组织为马氏体或铁素体+马氏体,母材区为索氏体+碳化物,且在其焊缝处发现存在δ相;焊接接头部位,焊缝区的硬度最高,热影响区的次之,母材区的硬度最低;焊接接头抗拉强度为707 MPa,屈服强度为579 MPa,断裂部位在热影响区。

P92 steel was welded by suitable welding process. The hardness, microstructure and tensile mechanical properties of the welded joint were analyzed by using the hardness tester, metallographic microscope and universal tensile testing machine. The results showed that the microstructure in the weld zone after welding of P92 steel was ferrite and martensite and carbide, the microstructure in the heat-affected zone was martensite or ferrite and martensite, and the base metal zone was soistenite and carbide. The hardness of the welded joint was the highest in the weld zone, followed by the heat-affected zone and the lowest in the base metal zone. The tensile strength of the welded joint was 707 MPa, the yield strength was 579 MPa, and the fracture was in the heat-affected zone.