喷丸处理Q235钢中晶粒尺寸与残余应力的关系预测

作为优异的表面处理工艺,喷丸表面处理能够提高金属表面性能,被广泛应用于航天航空领域。为了研究喷丸表面强化的内在物理机理,建立了喷丸冲击的力学模型,应用DYNA软件研究弹丸速度、半径和弹丸数量等因素对残余应力的影响。进一步利用Zener-Hollomon参数模型和动态再结晶公式计算出理论晶粒尺寸,并讨论残余应力与晶粒尺寸的演化规律。分析结果发现:弹丸速度、半径和弹丸数量的增大会使残余应力变大而晶粒尺寸相对变小。但并未发现残余应力与晶粒尺寸之间存在定量关系,表明这两种强化机制相互独立。

Prediction of Relationship Between Grain Size and Residual Stress in Shot Peening Q235 Steel

As an excellent surface treatment process, shot peening surface treatment can improve metal surface performance and is widely used in the aerospace field. In order to study the physical mechanism of shot peening surface strengthening, a mechanical model of shot peening impact was established. The DYNA software was used to study the impact of shot velocity, radius and number of shots on the residual stress. The Zener-Hollomon parameter model and dynamic recrystallization were further used. The formula calculates the theoretical grain size, and dis-cusses the evolution rule of residual stress and grain size. Results show that the increase of projectile velocity, radius and number of shot peening will make the residual stress larger and the grain size relatively smaller. Although the changes of residual stress and grain size are similar, there is no quantitative relationship between them, and these two strengthening mechanisms are independent of each other.