压力管道碳素钢与奥氏体不锈钢焊接存在的问题及防止措施

在压力管道施工过程中，碳素钢与不锈钢对接焊焊缝质量是施工的技术难点，两种不同材质的钢管对接时会产生焊缝金属稀释，熔合区出现脆性过渡层，存在碳的扩散迁移等，造成接头熔合区发生脆性断裂以及热疲劳等焊接质量问题。提出在碳素钢母材金属侧用含高铬镍焊条堆焊过度层来减小稀释和碳的迁移；采用U型坡口、小电流、高电压、快速焊和多层焊的焊接工艺来提高熔合比，减小稀释，提高焊接韧性，通过焊前预热和焊缝缓冷充分消除热应力等一系列防止措施。

The Existed Problem on Pressured Pipe Carbon Steel and Austenitic Stainless steel Welding and Preventive Measure

It is the technical difficulty of construction of weld quality for Carbon steel and stainless steel joint weld seam during the laying of pressured pipe.It will produce weld metal dilution,occurring brittleness transition tier in fusion area when two different material pipes joint welding and existed carbon diffuse and transfer,etc..This leads weld quality problem joint fusion area arises brittle fracture and heat fatigue,etc.A series of preventive measure is given by using high chrome-nickel content of welding rod stack transition layer on side of carbon steel parent metal to decrease dilution and carbon transfer and adopt the welding procedure of U type bevel,small current,high voltage,fast welding and multi-layer welding to increase ratio of fusion joint,reduce dilution and improve the welding toughness and through preheat before welding and weld postpone cooling to fully relive heat stress,etc..