母材含碳量对珠光体—奥氏体异种钢焊接熔合区形态的影响

The effect of carbon content in base-materials on bond pattern in welding Pearlite-Austenite dissimilar steel

用同一焊接规范制成A402在DT3、20#、45#、T8钢上单道堆焊样品,用显微硬度、SEM+EDS、TEM研究了母材含碳量不同时异种钢焊接熔合区的特征.实验结果表明:低碳钢母材接头熔合区由较平整的白亮带和针状类马氏体层组成;中、高碳钢母材接头熔合区由“锯齿形”组织和不完全混合区组成,其中,中碳钢母材接头的不完全混合区组织为类马氏体,高碳钢母材接头不完全混合区类马氏体层消失,为奥氏体.

This paper studies the character of dissimilar steels' welding bo nd using different base-material's carbon content with the method of microhardne ss, SEM+ EDS and TEM. The samples of single building up are made of the same we lding procedure in DT3, 20, 45, T8 style steel. The result shows, the bond of lo w carbon base-material consists of smooth white light zone and needle-like l ayer of Martensite, the bond of medium and high base-material consists of sawt ooth structure and unmixed zone, and in medium carbon steel, the bond of base-material is Martensite-like, the bond of the high is changed into austenite. A t last, the test result is discussed.