FV520(B)与18CrMnMoV焊接接头力学性能分析

Analysis of mechanical properties of FV520(B) stainless steel and 18CrMnMoV steel welded joints

对马氏体沉淀硬化不锈钢FV520(B)与18CrMnMoV异种钢焊接接头经过850℃油淬后,分别进行了560℃,600℃及630℃回火处理。通过拉伸试验、示波冲击试验、硬度试验对焊接接头的力学性能进行了试验研究。结果表明,三种焊接接头中焊缝硬度最高,与焊缝中粗大的过时效马氏体组织有关;随着回火温度的升高,焊缝的韧性提高;在焊缝两侧热影响区均存在软化区,FV520(B)母材侧软化区导致560℃,600℃回火的焊接接头拉伸试样在该区域断裂;600℃回火处理后的焊接接头具有比较合理的综合力学性能。

After being 850 ℃ oil quenched,dissimilar steel welded joints of FV520(B) and 18CrMnMoV were tempered at 560 ℃,600 ℃,630 ℃,respectively.The mechanical properties of welded joints were investigated with tensile test,instrumented impact test and hardness test.The results show that hardeness of the weld in three welded joints are respectively highest due to coarse over-aging martensite in welds.The toughness of weld is improved by the tempering temperature being increased.There are the soft zones in heat affection zone on both sides of the welds.The tensile specimens of welded joints tempered at 560 ℃ and 600 ℃ both failed in the soft zones beside martensitic precipitation-hardening stainless steel FV520(B).The matching of mechanical properties of the welded joint tempered at 600 ℃ are the most rational in three tempering conditions.