15CrMo钢换热器焊后分步局部热处理工艺

Post-welding Step-by-step Local Heat Treatment Process of 15CrMo Steel Heat Ex⁃changer

15CrMo钢固定管板式换热器在预制过程中进行整体焊后热处理,很容易引起换热管与管板的焊缝开裂。为解决这一问题,在查阅相关资料并结合多年制造经验的基础上,经几次试验制订了分步局部热处理的工艺,在热处理后的无损检测及压力试验过程中均没有发现换热管与管板的焊缝发生泄漏,极大地保证了产品质量。试验结果表明,对管程及壳程全部采用15CrMo钢的固定管板式换热器,并使用分步局部热处理的方式可达到预期的消除焊后应力的要求。对15CrMo钢制换热管与管板的焊缝采用分步局部加热方式,既可满足热处理工件均温性的要求,又可达到消除应力的目的,为制造该类换热器积累了经验,提高了同类产品的市场竞争力。

The 15CrMo steel fixed tube sheet heat exchanger undergoes overall post-welding heat treatment during the prefabrication process,which can easily cause cracking of the weld seam between the heat exchanger tube and the tube sheet.In order to solve this problem,the process of step-by-step local heat treatment is developed through several tests based on the relevant data and many years of man-ufacturing experience.In the process of non-destructive testing and pressure testing after heat treat-ment,there is no leakage of the weld seam between the heat exchanger tube and the tube sheet,which greatly ensures the quality of the product.The test results show that for the fixed tube sheet heat ex-changer with 15CrMo steel for both tube pass and shell pass,the step-by-step local heat treatment method can achieve the expected post-welding stress relief requirements.The weld seam of 15CrMo steel heat exchanger tube and tube sheet heated by step-by-step local heat treatment method can meet the requirements of temperature uniformity of heat-treated workpieces,and also can achieve the pur-pose of stress relief.