空调四通换向阀失效分析

空调四通换向阀是空调温控的主要器件之一，在水压试验过程中，发现一定比例的空调四通换向阀产品漏水失效，给企业的正常生产带来干扰和重大的经济损失。对失效产品进行检查、分析发现空调四通换向阀中的不锈钢封头有开裂，封头采用进口铁素体不锈钢棒材。本文通过金相、SEM、EDAX等先进显微分析技术，发现铁素体不锈钢棒材内部有大量的沿轴向分布的硫化锰夹杂物。空调四通换向阀失效是封头的开裂引起的，而封头的开裂与封头材料内部有大量轴向分布的硫化锰夹杂物有关。

Failure Analysis of 4-way Reversing Valve for Air-Condition

Some 4-way reversing valves are found with water leak failure after hydraulic-pressure testing. After check the stems made by imported ferric stainless steel bars inside the 4-way reversing valve had cracks, The cracking stems was studied by Metallngraphy, SEM and EDAX. It is found that there are a large quantity of sulfured manganese inclusions in the sample. Therefore, the water leak failure of 4-way reversing valve for airconditioning is caused by the cracking stems inside, which results form the large amount of sulfured manganese inclusions in the imported ferric stainless steel bars.