高強度小徑壁比SAWH鋼管結(jié)晶裂紋分析及控制措施

Analysis on Causes for Solidification Cracking of High Strength/Small DS Ratio SAWH Pipe and Relevant Control Measures

摘要: 針對X70鋼級、Φ813 mm×17.5 mm螺旋縫埋弧焊（SAWH）鋼管生產(chǎn)過程中出現(xiàn)的結(jié)晶裂紋，根據(jù)其形成機理，并結(jié)合生產(chǎn)工藝特點，分析了結(jié)晶裂紋產(chǎn)生的原因。通過減少成型應力、控制成型穩(wěn)定性、優(yōu)化焊縫形貌、降低焊接熱輸入量等措施，有效減少了結(jié)晶裂紋出現(xiàn)的頻次，為高強度、小徑壁比SAWH鋼管的生產(chǎn)積累了經(jīng)驗。

Abstract: Addressing the problem concerning the solidification cracks occurring with the X70 Φ813 mm×17.5 mm SAWH pipes during the manufacturing process, the causes are analyzed based on the formation mechanism of such defect, and the characteristics of manufacturing process of the pipe. Accordingly, countermeasures are determined and taken, including reducing formation stress, properly controlling formation consistency, optimizing weld pattern, and cutting down heat input for welding, etc. As a result, the occurrence frequency of the cracking is remarkably reduced. This experience is helpful for production of high strength/small DS ratio SAWH pipes.