时效温度对Fe-Cr-Ni-Cu模型合金脆化效应研究

Effect of Aging Temperature on Embrittlement of Fe-Cr-Ni-Cu Model Alloy

使用光学显微镜、维氏硬度计、扫描电子显微镜和示波冲击试验机等设备研究Fe-17Cr-Ni-Cu模型合金未经时效处理、475℃下时效500h、500℃下时效500h及540℃下时效500h样品的微观组织及力学性能。研究结果表明:随着时效温度的升高,板条马氏体组织越来越均匀,且时效过程中析出的富Cr铁素体是主要的致脆相;通过示波冲击曲线计算出动态冲击韧度,时效温度升高,动态断裂韧度增大;夏比冲击试样断口形貌也由未经时效处理的韧性转变为脆性,时效温度升高后又由脆性转变为韧性。

In this experiment,the microstructure and mechanical properties of Fe-17Cr-Ni-Cu model alloy aged at 475℃,500℃and 540℃for 500 h and untreated samples are studied by optical microscope,Vickers hardness tester,scanning electron microscope and oscillograph impact tester.The results show that with the increase of aging temperature,the microstructure of lath martensite becomes more and more uniform,and the Cr-rich ferrite precipitated during aging is the main brittle phase.The dynamic impact toughness is calculated by oscillographic impact curve.The higher the aging temperature,the greater the dynamic fracture toughness.The fracture morphology of Charpy impact specimen also changes from toughness without aging treatment to brittleness,and then changes from brittleness to toughness after aging temperature increases.