1Cr18Ni9Ti钢的低温拉伸变形行为

对1Cr18Ni9Ti钢在室温和低温下进行拉伸试验,利用TEM分析拉伸试样断口附近的显微组织,用SEM对拉伸断口进行观察,研究了温度对1Cr18Ni9Ti钢拉伸变形行为的影响.研究表明:随着试验温度的降低,1Cr18Ni9Ti钢的抗拉强度与屈服强度及加工硬化指数单调增加;延伸率呈降低趋势,并在温度降至77 K时略有回升;拉伸断口附近显微组织中出现板条马氏体,且温度降低,板条马氏体数量增加;低温与应变共同作用诱发板条马氏体形成是影响1Cr18Ni9Ti钢低温拉伸变形行为的重要因素.

Tensile deformation behavior of 1Cr18Ni9Ti steel at low temperatures

Tensile tests at room temperature and low temperatures (200,100 K and 77 K) for the 1Cr18Ni9Ti steel were carried out. The microstructure in the vicinity of tensile fracture surfaces were analyzed using TEM.The fractures of tensile samples were observed by SEM. The effects of low temperature on tensile deformation behavior of 1Cr18Ni9Ti steel were studied. Experimental results showed that with decreasing temperatures, tensile ultimate strength, yield strength and work hardening exponent of 1Cr18Ni9Ti steel monotonously increased, while the elongation showed a decreasing trend and slight increase at 77 K. Lath martensite appeared in the microstructure nearby the tensile fratures and its amount increased with decreasing temperature. The formation of lath martensite induced by low temperature and strain was the primary factor of inducing deformation behavior of 1Cr18Ni9Ti steel.