摘要
研究奥氏体耐热不锈钢SAVE25在700℃高温时效性能，采用金相显微镜（0M）、扫描显微镜（SEM）和x射线衍射（XRD）分析了SAVE25时效后金相组织、冲击断口形貌以及萃取后析出相的物相和晶体结构。结果表明：SAVE25在700℃时效后冲击韧性随时效时间的延长明显降低，超过500h后变化趋于平缓；SAVE25奥氏体晶粒随时效时间的延长明显粗化，c元素的扩散决定了晶粒的粗化速度；由于第二相粒子受界面能和应变能的影响，SAVE25时效后晶界M23C6随时效时间的延长由连续网状逐渐转变为沿晶界颗粒状分布。
The properties of SAVE25 austenitic stainless steel after aging at high temperature of 700 ℃ were studied in this paper. Optical microscope （OM）, scanning electron microscope （SEM） and X-ray diffraction （XRD） were used to analysis the microstructure, fracture morphology, precipitates and crystal structure of SAVE25 after aging. The results show that, the impact toughness of SAVE25 decreased significantly with the increasing of aging time when aging at 700 ℃. When aging more than 500h, the impact toughness changes gently. The grain size of SAVE25 obviously coarsen obviously with the aging time prolonged. The diffusion of C element determines the coarsening rate of grain. After aging, continuous mesh M23C6 on grain-boundary in SAVE25 transformed into a granular distribution along the grain-boundary, due to the second phase particles is affected by the interface energy and strain energy.
出处
《锅炉技术》
北大核心
2015年第A02期12-18,共7页
Boiler Technology
