GH150氩弧焊接头组织和力学不均匀性研究

研究了ＧＨ１５０合金对接氩弧焊接头显微组织和力学性能的不均匀性，用金相分析和微型剪切试验等方法得到了该焊接接头各区域的微观组织和力学性能分布特性。结果表明，该焊接接头中存在着比较严重的微观组织和力学性能不均匀性，其不均匀程度在熔合线附近最为严重。因而认为熔合区是该焊接接头力学性能最薄弱的部位。同时，由微型剪切试验所得到的力学性能梯度曲线还表明，ＧＨ１５０合金是一种高强度材料，其韧塑性却偏低；在焊接接头各区域中的强度指标变化不大，但是焊缝和热影响区的韧塑性比母材降低较多。其中，焊缝的剪切变形率降低２１．８％，剪切功降低２５．５％。

Study on the Nonuniformity of Microstructure and Mechanical Properties of GH150 Joint of Argon Arc Welding

The nonuniformity of microstructure and mechanical properties in the GH150 butt joint of argon arc welding is investigated by means of distribution in the welded zone measured by the metallographic study and microshear test. Experimental results show that there exist nonuniform mechanics and microstructure in the welded zone, and the degree of nonuniformity is most perious in the bond junction. It is, therefore,considered that the bonding region of welded joints is the weakest zone in mechanical properties. In addition, the mechanical property gradient curves measured by microshear test also show that alloy GH150 is a metal of high strength and low plastotoughness, and that the strength fluctuation of the welded zone is not very clear. The plastotoughness is much lower in the welded seam and heat affected zone than in the base metal. For instance, microshear deformation proportion is reduced about 21.8%, in the weld seam, and microshear work is reduced about 25.5%.