铝在渗铝钢焊接时的物理冶金行为

PHYSICO-METALLURGICAL BEHAVIOUR OF ALUMINUM IN WELDING OF CALORIZED STEEL

通过X-射线衍射、透射电镜(TEM)、扫描电镜(SEM)和电子探针(EPMA),等测试技术分析和讨论了铝对GL渗铝铜管焊接时Cr-Ni奥氏体焊缝金属组织和性能的影响。结果表明:GL渗铝钢渗铝层主要由FeAl,Fe_3Al和α-Fe(Al)固溶体组诚,晶粒细小,可焊性好;在渗铝钢焊接过程中,铝使Cr-Ni奥氏体焊缝金属中的δ铁素体的数量和形态发生变化,但在δ铁素体中并不富铝,铝元素在δ相和γ相中的分布是随机的。

Effects of aluminum on microstructureand propeties of the Cr-Ni austenital weld metal of calorized steel pipes are analyzed and discussed by means of X-ray diffractometer, TEM, SEM and EPMA etc. Experimental results indicate that the diffusion coating layer on calorized steel is mainly composed of FeAl phase, Fe_3Al phase and α-Fe(Al) solid solution. Crystalline grain is very small and weldability is better. During welding of calorized steel pipes, aluminum element may change the quantity and morphology of delta ferrite in weld metal of Cr-Ni austenite. However, the delta ferrite does not contain too much aluminum, and aluminum in ferrite and austenite is distributed at random.