摘要
利用超声疲劳实验方法研究了2种商业42CrMo钢和2种零夹杂42CrMo钢在不同热处理制度下的超长寿命疲劳性能.结果表明,42CrMo钢疲劳S-N曲线在106-109cyc范围内无平台出现,疲劳极限消失;零夹杂42CrMo钢在此寿命区间有明显的疲劳极限. SEM断口观察表明,42CrMo试样疲劳开裂大多起源于非金属夹杂物,而零夹杂42CrMo全部起源于基体表面.零夹杂42CrMo钢的最大特点是在2×106-109cyc内不易发生疲劳断裂,疲劳寿命的可靠性显著增加.
The ultra-long fatigue properties of four high strength 42CrMo steels, two of commercial and two of zero-inclusion, produced by different heat treatment procedures are studied. The experimental results illustrate that in the regime of 10(6)-10(9) cyc, two commercial steels have no horizontal asymptote in fatigue S-N curves, so the conventional fatigue limit eliminates, but the fatigue limit of two zero-inclusion steels exists. SEM analysis shows the fatigue crack initiates from nonmetallic inclusion for commercial 42CrMo steels, and from surface of the matrix for two zero-inclusion steels. In the regime of 2 x 10(6)-10(9) cyc, it is very difficult to fracture for zero-inclusion steels, and the reliability of fatigue life is substantially improved.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2005年第2期145-149,共5页
Acta Metallurgica Sinica
基金
国家重点基础研究发展规划资助项目2004CB619100
关键词
夹杂物
零夹杂钢
疲劳强度
疲劳极限
超长寿命
inclusion
zero-inclusion steel
fatigue strength
fatigue limit
ultra-long fatigue life
