摘要
某超超临界机组叶片使用的12%Cr系耐热钢调质处理后,常温力学性能及金相组织满足规范要求,但高温短时持久性能出现明显的分散性。为提高和稳定材料的高温持久性能,对典型的同炉次持久试样进行试验分析,以研究短时持久性能差异的影响因素。研究表明:材料短时持久断裂属于典型的蠕变断裂方式,短时持久强度下降与持久试验温度下板条间和晶界的碳化物粗化有密切关系,能谱分析进一步发现孔洞处脱落物B元素含量较高,达到19.98%,说明晶界的B在高温持久过程中开始向晶内迁移并形成含B的第二相质点,晶界强度明显削弱,在高温持久试验中会造成高温强度的迅速下降并快速断裂,断裂的位置大多是沿晶的,个别会在夹杂物或第二相造成的孔洞处萌生发展。
12%Cr heat-resistant steel used in the ultra supercritical set blade was quenched and tempered by vacuum heat treatment furnace, whose room temperature mechanical properties and metallographic structure supply the specific requirements. However, the high-temperature short-tlllie lasting performance generates the dispersion. To improve and steady the high temperature endurance performance of materials, the typical and same batch permanent specimens need organizing, fracturing and hardness test analysis so as to research influence factors on short-time lasting performance differences. The results show that the short-time rupture belongs to the typical creep fracture, and short lasting strength is closely related to endurance test temperatures between laths and grain boundary carbide coarsening. Energy spectrum results analysis further reveals that cast in the hole has high content to 19.98wt% B element, which mean that grain boundaries of the B in high temperature lasting process begins to migrate and forms in the crystal B containing second phase particle, and grain boundary strength is obviously weakened. The enduring high temperature experiment can cause high temperature strength rapid decline and fast fracturing. Location of the fracture is often along crystal, and the individual will be the inclusion or second-phase holes caused by initiation development.
出处
《热加工工艺》
CSCD
北大核心
2013年第12期169-171,共3页
Hot Working Technology
基金
德阳市2012年度重点科学技术研究项目(2012ZH011)
关键词
短时持久性能
12%Cr系耐热钢
碳化物粗化
断裂
short-time endurance performance
12%Cr heat-resistant steel
carbides coarsening
crack
