碳钢空冷器管子管板焊接接头湿硫化氢应力腐蚀开裂研究

ON STRESS CORROSION CRACKING OF TUBE END WELDED JOINTS FOR CARBON STEEL AIR-COOLED HEAT EXCHANGER IN WET H_(2)S SERVICE

针对炼油厂高压碳钢丝堵式空冷器管束的换热管与管板焊接接头在湿硫化氢环境运行过程中发生开裂泄漏的问题,文章结合丝堵式空冷器管束管箱的结构特点,从材料、管接头硬度、焊接工艺、焊后消除应力热处理等方面进行研究分析。分析认为,焊接接头的硬度超标是引起开裂的主要原因。针对上述原因,提出了较为实际可靠的防止管接头湿硫化氢应力腐蚀开裂的推荐要求并在企业实施,取得了很好的效果。

Leakage on the welded joint of tube to tubesheet occurs due to cracking in high pressure tube bundle with plug header of carbon steel air-cooled heat exchanger in wet H_(2)S service in refinery.Aiming at such problem,this paper carried out research and analysis in terms of material selection,tube joint hardness,welding process,post-welding heat treatment and so forth by combining the structural characteristics of the tubes and tube boxes of plug-channel air cooler.The analysis concluded that the hardness of the welded joint exceeding the standard was the main cause of cracking.In view of the above reasons,the paper proposed more practical and reliable recommended requirement to prevent wet H_(2)S stress corrosion cracking on the welded joint of tube to tube and the recommended requirement was implemented in enterprises.This has achieved good results.