我国微米级超细晶粒钢焊接技术的研究现状

介绍了微米级超细晶粒钢的主要特点及其焊接性试验研究。微米级超细晶粒钢的焊接问题主要表现为焊接热影响区(HAZ)的脆化和局部软化,严重影响了焊接接头与母材性能的匹配。采用低热输入的焊接方法,可以适当减小焊接HAZ宽度,并避免焊接热影响粗晶区的晶粒过度长大;焊接热循环参数对其焊接接头的性能具有重要影响。向焊缝中添加稳定的第二相粒子,可促进针状铁素体组织的形成,有利于改善焊接接头的组织及性能,提高焊缝的强度和韧性。

Current status of domestic welding technique on micron class ultra -fine grain steel

The main characteristics and experimental study on weldability of ultra - fine grain size (micron class) steel in our country were introduced. It is pointed that the main problems existed in welding are embrittlement and partial softening of weld heat affected zone. These factors would deeply influence the properties match between welded joint and matrix metal. Welding methods with low heat input are adopted, which may moderately reduce weld heat affected zone' s width and avoid grains in coarse - grain zone from growing excessively. The parameters of weld heat circle play an important role in the properties of welded joints. Adding steady second phase particles into weld seam could promote the formation of acicular ferrite, improve the tissues and properties of welded joint and heighten the strength and toughness of weld seam.