摘要
对1.25Cr0.5Mo钢进行520℃应力控制下的疲劳蠕变试验,应用频率分离法、应变能频率分离法进行了寿命预测,预测结果基本位于±2倍误差范围之内。对断口形貌进行了SEM分析,结果表明各种加载条件下的断口都有很多的韧窝和蠕变孔洞。当应力幅大于等于平均应力时,蠕变孔洞内壁上分布着同心条纹,且同心条纹的间距随着应力幅的减小而降低;当平均应力较大而应力幅较小时,蠕变孔洞近似各自独立形核长大;当应力幅略小于平均应力时,蠕变孔洞壁上间距较大的同心条纹是疲劳促进蠕变损伤的证据,而蠕变孔洞上少量脱落的颗粒,是蠕变加速疲劳损伤的证据。
By stress controlled fatigue - creep tests of 1.25Cr0.5Mo steel at 520℃, lives are predicted by frequency separation and strain energy frequency separation method. Most of prediction lie within a factor of ± × 2 comparing-with test data. Scanning electron microscopy analysis is conducted, and all fracture surfaces have lots of dimples and creep cavities. When stress amplitudes are bigger than or equal to mean stresses, concentric striations appear on the inner boundary of creep cavities, and spaces between striations become smaller and smaller with stress amplitudes. When stress amplitudes are much smaller than mean stresses, cavities induced by static creep grow up independently without any concentric striations. When stress amplitudes are less than mean stresses after a sort, concentric striations with large spaces is evidence that fatigue accelerates creep damage, and some broken particles is evidence that creep accelerates fatigue damage.
出处
《压力容器》
北大核心
2006年第3期6-9,共4页
Pressure Vessel Technology
基金
国家十五攻关项目(2004BA803B02-06)
社会公益基金(2004DIB2J051)
安徽省自然科学基金(050450405)资助
