桥头电厂7^#炉过热器管内表面裂纹原因分析

Analysis the crack on the inside pipe of the overheater for the Boiler in Qiaotou thermal power plant

青海省桥头发电厂７＃炉系武汉锅炉厂制造，１９８４年元月投产，过热器管材质为１２Ｃｒ１ＭｏＶ，规格４２×５ｍｍ，１９９６年１２月至１９９７年５月７＃炉过热器管发生了两次爆管事故，严重影响了电厂的安全经济运行。１９９８年６月７＃炉大修检查时发现过热器监视管内表面有许多小裂纹，为了防止爆管事故的发生，保障机组的安全经济运行，通过试验分析找出了裂纹缺陷产生的原因。为了防止因原材料缺陷造成电厂不必要的经济损失，建议电厂严格检测进厂原材料的质量。

During the heavy repair of the 7 # boiler in Qiaotou thermal power plant in July 1998 many cracks were discovered that resulted in the pipe exploding.The paper analyzes the cracks and find the cause,that is the bad quality of the rolling steel plates, and suggests that the inspection on the materials should be strengthened.