双模态晶粒尺寸结构不锈钢的单轴棘轮变形行为研究

Research on Uniaxial Ratcheting Behavior of Bimodal Grain Structured Austenitic Stainless Steel

双模态晶粒尺寸结构不锈钢具有强度高、韧性好的特点,成为发展高强、高韧性和耐疲劳损伤金属结构材料的重要方法。研究了通过机械球磨(MM)及热等静压(HIP)制备的双模态晶粒尺寸结构316L不锈钢在室温下的单轴棘轮变形。结果表明:通过调控机械球磨时间,可制备出具有不同晶粒尺寸和体积分数的双模态晶粒尺寸结构316不锈钢。双模态晶粒尺寸结构316L不锈钢具有良好的强度和塑性。晶粒尺寸、平均应力和峰值应力保持时间都影响着棘轮应变的累积。

Stainless steels with bimodal grain size distribution have good balance of high strength and high ductility.It is an effective method for creating metallic structure materials which having excellent mechanical properties.Bimodal structured 316L stainless steels were fabricated by mechanical milling(MM)and subsequent hot isostatic sintering(HIP).The ratcheting behavior of bimodal structured 316L steels was investigated at room temperature.The results show that the grain size and volume fraction could be controlled by mechanical milling time.The bimodal structured 316L steels have good balance of strength and ductility.The gain size,mean stress and peak stress holding time affect the ratcheting strain accumulation.