大热输入条件下焊接材料熔敷金属韧性的变化及其控制

Change and control of deposited metal toughness of welding consumables under the high heat input conditions

分析焊接热输入与熔敷金属韧性间的关系,探讨大热输入条件下熔敷金属韧性的影响因素及控制方法。研究表明,常规热输入与焊接材料熔敷金属间的关系取决于焊缝中针状铁素体AF含量,AF含量高韧性好,否则韧性差。焊缝中一定量的Ti、B、Ce、N、O、H等元素在焊接过程中的冶金作用是获得大热输入条件下满意熔敷金属低温韧性的重要影响因素。从选择添加元素、探讨韧化机理、试验确定焊缝中元素精准含量等方面入手的控制熔敷金属韧性原理,其终极目标是使焊缝金属获得85%以上AF组织。

The relationships between welding heat input and deposited metal toughness were analyzed ,and the influence factors and control methods of deposited metal toughness under high heat input condition were discussed.The investigation shows that the relationships between the conventional heat input and deposited metal toughness for welding consumables depend on the acicular ferrite content in weld,when the acicular ferrite content is high the toughness is good,otherwise the toughness is poor. The metallurgical effects of a certain amount of Ti,B,Ce,N,O,H and other elements in the weld metal in welding process are an important influence factor to obtain satisfactory low temperature toughness of deposited metal under high heat input condition.The ultimate goal of controlling deposited metal toughness from the choice of adding elements ,discuss the toughening mechanism, test to determine the elements accurate content and other aspects is to obtain more than 85% AF microstructure of the weld metal.