ZG40Cr25Ni20奥氏体耐热钢的烧损研究

发布时间：2018-03-11 22:23

  本文选题：奥氏体耐热钢　切入点：碳化物　出处：《材料热处理学报》2017年02期 　论文类型：期刊论文

【摘要】：采用光学显微镜(OM)、能谱仪(EDS)、X射线衍射仪(XRD)、高温显微镜原位观察等实验手段,分析了ZG40Cr25Ni20奥氏体耐热钢烧损原因。结果表明,随着温度升高,奥氏体晶粒不断长大,碳化物Cr23C6不断形成和长大,碳化物中的Cr含量和碳化物硬度不断增加,奥氏体基体中的Cr含量不断减少。温度过高,碳化物溶解,形成孔洞,促进微裂纹沿晶界的扩展,奥氏体晶粒间的结合力逐渐减弱,基体发生过烧,钢的结晶组织遭到破坏,失去金属原有的塑性和强度,造成高温耐热管失效,孔洞和微裂纹的形成及扩展是材料失效的主要原因。此外,高温显微镜原位观察和热处理实验结果表明,ZG40Cr25Ni20耐热钢中碳化物的溶解温度为1030~1250℃。高温显微镜原位观察为碳化物溶解观察和耐热钢失效分析提供了一种新的方法。
[Abstract]:The causes of burning loss of ZG40Cr25Ni20 austenitic heat-resistant steel are analyzed by means of optical microscope, energy spectrometer, EDS-X ray diffractometer and in situ observation of high temperature microscope. The results show that the austenite grain grows with the increase of temperature. The formation and growth of carbides Cr23C6, the increase of Cr content and hardness of carbides, the decrease of Cr content in austenitic matrix, the dissolution of carbides at too high temperature, the formation of pores, and the propagation of microcracks along grain boundaries. The adhesion between austenitic grains is gradually weakened, the matrix is overburned, the crystalline structure of the steel is destroyed, and the original plasticity and strength of the metal are lost, which results in the failure of the heat-resistant pipe at high temperature. The formation and propagation of pores and microcracks are the main causes of material failure. The in-situ observation of high temperature microscope and heat treatment experiment show that the dissolution temperature of carbides in ZG40Cr25Ni20 heat-resistant steel is 1030 ~ 1250 鈩，

本文编号：1600197