温州化工厂碳钢列文式碱液蒸发器,温度为140℃左右,介质为31%NaOH浓缩到42%,用于钾肥生产。一台壁厚为6mm的新设备,最多在一星期内就沿焊缝两侧出现许多纵向或横向裂纹,裂纹从内壁向外贯穿,沿母材扩展,主裂纹边缘尚有许多细小的分枝。补焊后1～2天内又出现裂纹,有些裂纹宽达1～2mm,长达80～90mm,补焊频繁,应力腐蚀极为严重。 Wenzhou chemical plant carbon steel column type lye evaporator, the temperature is about 140 ℃, the medium is concentrated to 42% 31% NaOH for potash production. A new device with a wall thickness of 6 mm will have many longitudinal or transverse cracks along the weld within a maximum of one week. The cracks will extend from the inner wall to the outside and will spread along the base material. There are many small branches at the edge of the main crack . Crack occurs again within 1 ~ 2 days after welding. Some cracks are as wide as 1 ~ 2mm and up to 80 ~ 90mm. The welding is frequent and the stress corrosion is very serious.