摘要
本文通过金相分析证实水冷壁管环向裂纹产生的原因是高温造成管材表面脱碳、组织粗化、强度降低，同时产生管内部腐蚀，在交变热应力循环下，在管外向火侧产生裂纹并向内扩展，最后形成穿透裂纹。
Failure analysis was carried out on the circular cracking of pipes used on the water cooled wall of a boiler.Results of metallographic examination show that surface decarbonization,structure coarsening and strength deterioration at high temperature.together with corrosion at the inner surface have caused the cracks to initiate at the outer surface under cyclic thermal stress, and gradually propagated inward until the formation of a through crack.
