Improvement of welded joint property by a new welding technology - Development of a new concept LTT wire and UNGW process for UFG steels

摘要

The welding technology is important to produce structures by using high quality materials such as Ultra-Fine Grain Steels (UFG steels). The following weld materials and welding processes are important, (i) High quality'weld metal which can improve the joint properties, (ii) Small heat input welding process which can reduce deterioration of material properties. We can make high quality joints by combination of these. First, we describe a new concept of welding wire by which we can achieve excellent weld metal properties. Next, we show Ultra-Narrow Gap Welding (UNGW) which makes it possible to minimize heat input.