The present of scale and rust on the inside tube wall led to the pits and penetration of the tubed wall due to corrosion beneath scale.

• 水垢与锈垢的形成导致传热管内壁金属受到垢下腐蚀,垢下腐蚀对金属材料的穿进速度大,形成凹坑以至穿孔。