某奥氏体不锈钢压力容器硬度异常分析

Analysis Of Abnormal Hardness For An Austenitic Stainless Steel Pressure Vessel

文中利用硬度检测、材料元素分析、材料铁素体含量检测、金相分析和封头内外表面100%渗透检测等方法对某硬度异常的奥氏体不锈钢容器进行检测,结果发现封头直边段硬度最高,超过了标准限定值,封头中心处硬度值最低;材料铁素体含量与硬度值成近似线性关系;金相分析结果表明奥氏体晶粒有沿加工方向破碎、滑移面及晶界上产生大量位错现象,产生针状马氏体。通过分析发现这是由于封头加工时经过冷冲压工艺后没有进行固溶处理导致大量形变马氏体产生。根据分析结果对该类设备制造和使用过程提出两点建议。

In this paper, hardness testing, material element analysis, ferrite content testing, metallographic analysis and 100% penetration testing on the inner and outer surface of an austenitic stainless steel container with abnormal hardness were used. The results showed that the hardness of the straight side of the head was the highest, exceeding the standard limit value, and the hardness of the center of the head was the lowest. The ferrite content of the material was approximately linear with the hardness value. The results of metallographic analysis show that the austenite grains are broken along the processing direction, and a large number of dislocations occur on the slip surface and grain boundary, resulting in acicular martensite. Through analysis, it is found that a large amount of deformed martensite is produced because the head is processed by cold stamping without solid solution treatment. According to the analysis results, some suggestions are put forward for the manufacturing and using process of this kind of equipment.