工作介质中材料的应力腐蚀性能

为了研究某材料在工作介质中的应力腐蚀问题,开展了光滑试样和中心穿透预裂纹试样在温度为T_0、不同试验介质中、施加一定预应力水平的恒载荷试验,测试试样的力学性能,分析其金相组织,并测量了预裂纹试样在恒载试验过程中裂纹的扩展量.结果表明:在不同试验介质中,施加(90～95)% σ0.2载荷的光滑试样和施加(30～90)% K_c载荷的预制裂纹试样,经过约13000 h的试验后,没有试样发生滞后断裂,试验前后材料的抗拉强度、断裂韧性没有发生显著性变化;预制裂纹试样在恒载过程中裂纹向前扩展,扩展速率在10~(-5) mm/h的数量级;材料在工作介质中不存在应力腐蚀.

Stress Corrosion Behaviors of Materials in Working Gases

In order to investigate the behaviors of material in working gases, a series of experiments were conducted for samples with smooth shape and with prepared crack. Testing conditions include temperature T_0, different types of gases and various levels of pre-stress. Mechanical properties were tested and microstructure were analyzed. Expansion of the cracks under dead load was measured quantitively. The results show that:(1) No lag fracture was observed in the smooth shape samples under (90～95)% σ0.2 load for 1300 h, and in the prepared crack samples under (30～90)%Kc load. There was not significant change in the tensile strength and fracture toughness. (2) The prepared cracks were expanding under dead load, with the rate of about 10~(-5) mm/h. (3) No stress corrosion happened to the material in working gases within experiment.