结构极限承载与微观金相特征的关系

针对承压设备寿命评估和挖潜的重要工程意义,以压力容器典型材料16MnR为研究对象,采用宏观实验、不同变形阶段的微观及磁记忆跟踪检测、有限元数值模拟相结合的方法,从多角度评估结构塑性极限载荷.采用夏比冲击试样,测定0、5%、10%、15%、20%预应变状态下的时效冲击敏感性;对带双边孔缺陷试件进行拉伸试验,实时观察拉伸过程中缺陷处表面金相及磁记忆信号变化,应用有限元进行数值模拟.结果表明:该材料具有优良的延展性,在预应变15%的强化中期,KV2降低了23.1%;结构极限承载与微观金相特征有密切关系,当表面金相出现"沟壑"时,结构局部承受载荷接近材料的抗拉强度,与有限元模拟结果基本吻合;该材料在压力容器实际应用中,承载极限还有很大的挖掘潜力.

Analysis of the Relationship Between the Limit Load of Structure and the Microscopic Character

To analysis the maximum load and allowable load of typical pressure bearing structure,confirm the load-bearing capacity of pressure vessels,the relationship between limit load of structure and microscopic character of typical material 16MnR,which is widely used in pressure vessels,is studied in this paper.Macrotrial method,Microscopic observation,Magnetic memory testing and FEM are used. Metallic materials-Charpy notch impact test is done to inspect the sensitivity of the impact of aging at ambient temperat...