提高P91耐热钢焊接接头冲击韧度的研究

Study on Raising Impact Toughness of Welded Joint of P91 Heat-resistant Steel

探讨了影响P91耐热钢焊接接头冲击韧度的工艺因素,对P91钢的常规焊接工艺进行调整,并模拟该工艺进行焊接试验。最后通过拉伸、弯曲、冲击试验、断口扫描和金相观察检验接头组织及性能。结果表明,在模拟焊接工艺下,P91耐热钢可以获得良好的焊接接头。焊缝拉伸强度高于母材;焊缝侧向弯曲试验外弧面未发现开裂;焊接接头的显微组织为回火板条马氏体,未出现非正常组织,焊缝晶粒明显细化;接头冲击韧度得到了大幅度提高。

The process factors which affected the impact toughness of welded joint of P91 heat-resistant steel were approached, common welding technology of P91 steel was adjusted, and the welding test was carried out by the simulating process. The microstructure and mechanical properties of the welded joint were tested and analyzed by tensile, bending, impact testing, scanning electron microscope （SEM） of fracture surface and microscope. The results indicate that the good welded joint of P91 heat-resistant steel can be obtained by simulation welding technology. The tensile strength of welding seam is higher than that of the base metal. No crack appeares on the outside arc surface of welding seam in bending test. The microstructure of the welded joint is tempered martensite, no normal structure appeares and the welding seam grain is fined, the impact toughness of welded joint at the room temperature is greatly raised.