直縫埋弧焊管焊縫產(chǎn)生咬邊缺陷原因分析

Investigation of Causes for Defective Undercut of SAWL Pipe

摘要: 介紹了直縫埋弧焊管產(chǎn)生咬邊缺陷的6種情況，并在此基礎(chǔ)上分析了咬邊缺陷的產(chǎn)生原因，提出具體的控制措施。分析認(rèn)為：產(chǎn)生咬邊缺陷的主要原因是在焊接時熔池受力情況發(fā)生改變，導(dǎo)致液態(tài)金屬流動范圍縮小或流動方向改變；通過調(diào)整焊接工藝參數(shù)、坡口位置、焊絲角度，以及使焊絲軸線與坡口橫截面垂直或采用細(xì)絲焊接等措施，可減少咬邊缺陷。

Abstract: The common six types of the defective undercuts of the SAWL pipe are described here in the paper，based on which the causes for the said defect are investigated.And accordingly，specific preventative actions are proposed.The analysis result reveals that the major cause for the defective undercut of the pipe is that it is the stress changing of the molten bath during welding operation that causes reduction of the molten metal flow area or change of the flow direction.Accordingly，the defective undercut can be lessened by means of such actions as adjusting the process parameters，bevel position，and welding wire angle，and getting the welding wire axis perpendicular to the bevel cross section or adopting some thin welding wire.