三元复合驱转油站加热炉火管开裂原因分析  

Cracking Failure Analysis on Fire Tube of Fire Cartridge Heater of Alkaline-Surfactant-Polymer Flooding

作　　者：何树全[1] 

机构地区：[1]中国石油天然气股份有限公司大庆油田工程有限公司,黑龙江大庆163712

出　　处：《石油化工腐蚀与防护》2014年第5期59-63,共5页Corrosion & Protection In Petrochemical Industry

摘　　要：采用扫描电镜、能谱及X-射线衍射仪等方法,分析了材质、腐蚀产物、裂纹及断口的金相组织、微观形貌及成分组成,结合对加热炉工艺及设备概况、工艺条件、输送介质、事故发生过程等要素的全面调查,明确了加热炉火管开裂失效的原因,并提出了相应的防护措施建议.经综合分析后认为：火管外壁附着16～17 cm软质淤积物,以及1～3 cm的硬质碳酸盐垢物,造成内壁热传递受阻,在火管刚脱离耐火砖衬层保护处产生局部过热,形成1～8 mm的黑色高温氧化产物,分层脱落,导致管壁局部减薄至1 ～2 mm;同时,高温使金相组织粗大的焊缝热影响区产生再热裂纹,最终导致火管焊缝热影响区短期内发生开裂失效.建议改进清垢、清淤措施,避免火管局部温度超过475℃;改善焊接工艺,避免焊缝热影响区组织粗大,以防止类似的事故再次发生.The metallurgy, corrosion products, cracks, fracture metallographic structure, micro morphology and compositions are analyzed by scanning electron microscope （ SEM ）, energy dispersive spectrometry （EDS） and X - ray diffractometer （ XRD ）. The causes of cracking failure of fire tubes of fire cartridge heater are found out through investigations of heater equipment conditions, process conditions, media conditions and accident process, and corresponding prevention measures are suggested. The results show that local overheating was caused by heat transfer blocked by the soft deposit 16 ~ 17 cm thick and hard carbonate fouling 1 ~ 3 cm thick on the external wall of fire tubes. The temperature became higher and higher in the location where there was no protection of firebrick lining. The black high - temperature oxides which was 1 ~ 8 mm thick were formed and spalled, leading to a 1 - 2 mm thinning of tube wall. At the same time, the reheat cracking occurred in weld heat - affected zone where there was bulky microstructure. All these eventually led to the cracking failure in the heat - affected zone of welds of fire tubes in the short tenn. It is recommended to improve fouling cleaning and deposit cleaning measures to prevent the local temperature of fire tube from exceeding 475 ℃ , and improve the welding process to prevent the large heat - affect zone so as to prevent re- occurrence of the same accidents.

关 键 词：三元复合驱 火筒式加热炉 火管 失效分析 

分 类 号：TE934[石油与天然气工程—石油机械设备]