摘要
采用透射电镜观察、示波冲击试验、硬度试验等方法,研究了经850℃中间调整处理后,不同时效温度对FV520(B)沉淀硬化不锈钢的组织和性能的影响。结果表明,在420℃时效,硬度出现峰值,主要与组织中细小的富铜相共格析出有关。随着时效温度提高,富铜相逐步脱溶长大、基体再结晶,硬度逐步降低。FV520(B)钢的冲击总功主要决定于裂纹扩展功,时效组织对FV520(B)钢冲击裂纹萌生功影响较小,对裂纹扩展功有着较大的影响。420℃及470℃时效状态下的冲击试样扩展区断口以解理形貌为主,而其它时效状态下为韧窝形貌,但韧窝细节各不相同。
The effects of different ageing processes on microstructure and properties of precipitation-hardening stainless steel FV520 （B） after 850℃ intermediate treatment were investigated by TEM, oscillo-impact test and hardness test. The results show that the hardness reaches a peak value at 420℃ ageing due to fine copper-rich phase precipitating. However, the hardness decreases gradually along with the ageing temperature increase because of the copper-rich phase precipitating,coarsening and matrix recrystallizing. The total impact energy of FV520 （B） steel mainly depends on the crack propagation energy, the effect of ageing microstructure on impact crack initiation energy is small but on crack propagation energy is big. The fracture appearance of the impact specimens aged at 420℃ and 470℃ is mainly cleavage, while those of the specimens aged at other temperatures are dimples, but the dimples have differences in detail.
出处
《金属热处理》
EI
CAS
CSCD
北大核心
2007年第4期30-33,共4页
Heat Treatment of Metals
关键词
沉淀硬化
时效处理
微观组织
示波冲击试验
precipitatation-hardening
ageing
microstructure
oscillo-impact test
