NM360钢与Q345钢异种钢焊接接头组织与性能研究

Microstructure and properties of the welding joint between NM360 steel and Q345 steel after MAG

为了解NM360钢与异种钢焊接应用过程中焊接接头的力学性能,本文对NM360调质钢和Q345热轧钢采用气体保护焊进行异种钢焊接,对焊接接头进行了力学性能试验及微观组织观察,并分析了NM360钢ICHAZ的软化机理.研究表明:Q345热轧钢焊接接头CGHAZ组织为贝氏体+魏氏组织,为HAZ硬度值最高的区域,FGHAZ和ICHAZ组织为P+F;NM360调质钢焊接接头CGHAZ组织为低碳马氏体,FGHAZ组织为低碳马氏体+少量的粒状贝氏体,晶粒细小,为HAZ硬度值最高的区域,ICHAZ组织为回火马氏体+铁素体+粒状贝氏体,铁素体组织是造成ICHAZ硬度值大幅度降低的原因.

To understand the mechanical properties of welding joint between NM360 steel and another dissimilar steel, this paper welded NM360 steel and Q345 steel by using GMA and analyzed the welded joints mechanical properties, microstructure, and the ICHAZ softening mechanism. The results show that Q345 steel welded joints CGHAZ organization is bainitic and Wildmanstatten structure which is the highest HAZ hardness values, FGHAZ and ICHAZ organization is P and F;NM360 steel CGHAZ organization of welded joints is low carbon martensitic, FGHAZ organization is low carbon martensitic and a small amount of granular bainite which is HAZ hardness value area of the highest for fine grain, ICHAZ organization is ferrite, granular bainite and tempered martensite, the ferrite makes ICHAZ hardness values significantly reduced.