喷丸除锈过程及效果的数值模拟研究

Numerical Simulations on Process and Effectiveness of Rust Removal by Shot Blasting

目的模拟研究喷丸除锈工艺的过程和处理效果,为优化工艺参数提供指引。方法以建筑用低碳钢及其锈蚀产物为研究对象,利用单元去除技术和周期性胞元方法建立有限元模型,模拟多个丸粒随机撞击和氧化层去除的过程,并与文献中的实验数据进行了对比验证,从氧化层去除速率、去除后的表面粗糙度和表层残余应力三个角度分析喷丸除锈工艺的效果。结果提高除锈效果可从增大丸粒入射速度和丸粒直径来入手,氧化层越厚喷丸除锈处理的时间越长。结论喷丸除锈工艺能有效去除锈蚀层,同时改善表面粗糙度和引入残余压应力,具有较广的应用前景。有限元模拟能为该工艺优化提供便捷的研究途径。

The work aims to investigate into the process and effectiveness of rust removal technique by shot blasting based on numerical simulations so as to direct the optimization of technological parameters. While low-carbon steel for building and its corrosion products were taken as the object of study, finite element（FE） models were established by utilizing the element removal technique and periodic cell algorithm, so as to simulate the rust removal process for the mild steel under the random impact of various shots. The simulations were validated by comparing the results with the experimental data in literatures. The effectiveness of the shot blasting in rust removal was examined in terms of rust removing rate, residual stress distribution and surface roughness. The effectiveness of shot blasting treatment was improved by increasing kinetic energy of the impinging shots, i.e. the incident velocity and shot diameter. Longer shot blasting treatment was required to remove the rust for thicker oxide layer. Shot blasting is an efficient technique to remove the rust coating, improve the surface roughness and introduce the compressive residual stress. Hence it has promising application prospect. FE simulation is a useful tool to provide flexible study approach for optimizing the process.