304不锈钢应变强化疲劳寿命的试验研究

EXPERIMENTAL STUDY OF 304 STAINLESS STEEL FATIGUE LIFE CONSIDERING MATERIAL PRE-STRAIN HARDENING EFFECT

不锈钢应变强化压力容器广泛应用到液态气体的储存和运输,研究应变强化不锈钢材料的疲劳寿命对保证该类结构的安全运行具有重要的意义。分别对室温下304不锈钢未预应变强化、10%预应变强化和15%预应变强化三类材料进行了应变控制下的低周疲劳寿命测试,应变幅值变化范围为±0.3%到±0.7%。从试验结果中获得了三种情况下材料的疲劳特性和疲劳S-N曲线,并与ASME BPVC VIII-2等标准进行了对比,发现采用预应变强化疲劳寿命设计曲线进行评价可以提高结构的设计疲劳寿命。

304 stainless steel （304 SS） strain-hardening pressure vessels are widely used to store and transport liquefied gas. It is important to investigate the fatigue properties of strain hardening pressure vessels. In this paper, low-cycle fatigue tests under strain-controlled of 304 SS pre-strain hardening materials are performed. In the test, the pre-strain are 10% and 15% , and the total strain amplitudes range from ±0. 3 to ±0. 7%. According to the test results, the S-N curves of pre-strain hardening material are obtained, and then compared with the design curves in ASME BPVC VⅢ2 code. It can be found that the designed fatigue life can be improved when the equipments are evaluated with the pre-strain hardening fatigue life design curve.