论文部分内容阅读
采用MTS材料试验机研究作为反应堆结构材料的316奥氏体不锈钢母材在350℃和室温,以及焊缝在室温,±0.3%~1.5%应变幅的低周疲劳性能试验,并采用扫描电镜对试验后样品进行了断口分析。研究结果表明,316不锈钢疲劳性能较好,室温下疲劳寿命高出350℃同一应变幅的30%~50%以上,且母材的疲劳寿命显著高出焊缝同一应变幅的一倍以上。随应变幅的增加,材料疲劳寿命相应下降,峰值应力增加。室温下母材和焊缝均呈现出随循环周次增加、峰值随应力逐渐下降的规律。母材在高温下,随应变幅的增加,逐渐由循环硬化过渡到饱和行为。低周疲劳试验后,断口表面可观察到裂纹源和疲劳条带。随应变幅增加,疲劳条带间距增大,且同一应变幅下,焊缝的间距大于母材,高温的疲劳间距大于室温,与疲劳试验结果相吻合。
The MTS material testing machine was used to study the low cycle fatigue properties of 316 austenitic stainless steel base metal used as reactor structural material at 350 ℃ and room temperature, and the strain range of ± 0.3% ~ 1.5% at room temperature. Scanning electron microscopy After the test sample fracture analysis. The results show that the fatigue life of 316 stainless steel is better, the fatigue life at room temperature is higher than 30% ~ 50% of the same strain amplitude at 350 ℃, and the fatigue life of base metal is more than double that of the same strain of weld. With the increase of amplitude, the fatigue life of the material decreases correspondingly, and the peak stress increases. At room temperature, both the base metal and the weld appeared to increase with the cycle and the peak value gradually decreased with the stress. Base metal at high temperature, with the increase of amplitude, gradual transition from hardening to saturation behavior. After the low cycle fatigue test, the fracture surface can be observed crack sources and fatigue bands. With the increase of the amplitude, the fatigue band spacing increases, and the same strain amplitude, the weld spacing greater than the base metal, high temperature fatigue spacing greater than room temperature, consistent with the fatigue test results.