基于红外热像显微观测技术的304不锈钢疲劳性能研究

Study on the 304 Stainless Steel Fatigue Performance Based on the Infrared Thermal Image Microscopy Observation Technology

借助红外热像仪和远场视频显微镜研究了304奥氏体不锈钢应力疲劳的温度响应与微观形貌变化规律,运用扫描电镜对试件断口进行微观分析。研究结果表明:载荷幅值对试样表面最大温升有一定影响,试件表面温度变化与微观形貌的演化之间存在相关性。随着应力水平的增加,试样断口裂纹扩展区疲劳条带变窄,瞬断区韧窝增多。

In virtue of the infrared thermal imager and far-field video microscope,both temperature response and surface morphology evolution rules of the 304 austenitic stainless steel stress fatigue were investigated andthe microscopic analysis of the fracture with scanning electron microscope was carried out. The results show that,the load amplitude has certain effect on the sample surface＇s maximum temperature rise; and the surface＇s temperature change closely relates to the evolution of the microstructure. With the increase of stress level,at the crack propagation region of sample fracture fatigue,the fatigue striations narrow down and the dimples get increased in instantaneous fracture regions.