新型EH40船板钢大热输入量埋弧焊焊接接头组织性能研究

Study on Microstructure and Properties of EH40 Ship Steel Plate Welding Joint by Submerge-arc Welding Process with High Heat-input

对EH40船板钢埋弧焊焊接接头的组织性能进行了试验分析。结果表明:以60 kJ/cm的焊接热输入量焊接,接头的强度高于母材,热影响区(HAZ)没有出现焊接软化区。HAZ的低温冲击韧度低于母材,其中靠近熔合线的粗晶区冲击值(85.2 J)最低,远离熔合线4 mm处的冲击值(246.0 J)已接近于母材。HAZ的组织状态对接头力学性能有较大影响。母材中Ti、Nb合金元素生成的碳、氮化合物在一定程度上改善了HAZ的韧性。

The microstructure and properties of welded joint of EH40 grade ship steel plate by submerged-arc welding process were analyzed. Experiment results show that strength of the joint is better than basic material and there isn＇t soft zone in HAZ with the high heat-input 60 kJ/cm. The impact toughness in the HAZ is lower than the basic material. The lowest toughness value （85.2 J） is in coarse grain zone near the fusion line, and the toughness value （246.0 J） approaches to the basic material＇s in the zone which is 4mm far from the fusion line .The microstructure in the HAZ has great effect on the mechanical properties of the joint. The toughness in the HAZ is improved because of the existence of carbides and nitrides of the alloying elements Ti and Nb.