王志刚 琚丹丹 忽俊成 郑维信 王岑

摘要： 某苯乙烯项目反应器在制造过程中，发现S30409钢制椭圆形封头在经过热冲压和冷旋压成形后直边区硬度超标、铁素体数偏高等现象。文中采用Simufact建立模型，对封头成形过程进行模拟应力分布情况分析，并对封头直边段区域的显微组织、硬度及铁素体数等进行试验。结果表明，封头直边部位发生了较大塑性变形，应力值较高，且该部位金属材料组织也发生了变化，易在制造、服役等过程中发生开裂等问题，对封头重新进行了整体固溶处理后可恢复性能。

关键词： 不锈钢封头; 冷旋压; 固溶处理

中图分类号： TG 406

Abstract： During the manufacturing process of a styrene project reactor， it was found that the hardness and ferrite number of the S30409 steel head on straight edge area exceeded the standard after hot stamping and cold spinning. In this paper， Simufact was used to establish a model to simulate and analyze the distribution of stress during forming process of the head. And tests of microstructure， hardness and ferrite number were carried out on the area of the straight side of the head. The results showed that the straight edge of the head appeared a large plastic deformation and a high stress value. And microstructure of the part was also changed， which was liable to crack in the process of manufacturing and service. The properties of head could be recovered by the whole solution treatment.

Key words： stainless steel head; cold spinning; solution treatment

0 前言

承壓设备的封头大部分都是通过旋压或冲压的工艺方式制作而成[1-3]。由于奥氏体不锈钢的韧性较强，所以在旋压或冲压时，不需要提前对钢板进行加热处理，这样的加工方式称为冷冲压和冷旋压。若采用在塑性变形之前对钢板材料进行加热处理，这样的加工方式为热冲压和热旋压[4-8]。谢晓芳等人[1]的研究认为冷旋压过程中，力的反复作用使其发生冷作硬化，提出变形应控制在15%以内，甚至更小;瞿金辉等人[2]的研究发现，304封头直边段裂纹主要是形变诱导马氏体相使得该部位应力极具升高，直至裂纹形成和扩展;张雪涛等人[4]对北海封头生产发生开裂失效的奥氏体不锈钢封头各部位进行了铁素体测定，发现变形率较低区域封头底部、变形率5%的区域有少量相变马氏体，而直边段已有大量相变马氏体。……