奥氏体不锈钢换热管束管头开裂的修复实践

Repair practice on tube head cracking of austenitic stainless steel heat exchange tube bundle

换热器受运行温度高、压力大、温差应力引起的热胀冷缩及腐蚀性介质等因素的影响,其管板和换热管焊接接头极易产生裂纹。以某柴油加氢裂化装置U型管式高压换热器为例,开展奥氏体不锈钢换热管束管头腐蚀开裂的修复研究与实践。通过理论分析、强度校核,制订了合理的修复方案;经渗透检测、脱氢热处理、机械加工、管头焊接等使缺陷得以修复。经过半年的实际运行,证明修复效果良好。

Cracks occur easily at the welding heads of heat exchange tubes and the tube plate of heat exchanger due to high temperature,high pressure and temperature stress as well as influence of corrosive medium.Taking the U type tubular high-pressure exchanger at a diesel hydrogenation unit for example,this paper conducts the research on tube head corrosive cracking of the austenitic stainless steel heat exchange tube bundle.The rational repair scheme is worked out through theoretical analysis and strength check.And by means of penetrant testing,dehydrogenation treatment,machining and tube head welding,the cracks are repaired.The practical operation of the heat exchanger for half a year proves the repair achieves the expected goal.