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利用有限元法对高强度珠光体钢丝冷拔残余应力应变进行有限元分析,在此基础上利用有限差分法计算应力应变同时诱导下的氢扩散浓度分布规律,并比较其与只考虑残余应力诱导氢扩散模型所得氢浓度分布规律的不同。结果表明,由于冷拔加工过程中钢丝表面和内部变形速率的差异,冷拔后在钢丝表面产生较大的残余拉应力和大量的塑性应变。残余应力应变的存在,加剧氢在材料中的扩散和聚集,其中应变的影响相当明显。在短时间内,由于塑性应变降低氢在材料内的扩散系数,所以同时考虑残余应力和应变引起的氢富集水平低于只考虑应力诱导引起的氢富集水平。随着时间的增加,应力应变引起的氢富集浓度明显大于只考虑应力诱导时的氢富集浓度。塑性应变会引起氢富集已经被大量实验所证实,同时考虑应力应变对氢扩散的影响更具有实际意义,为进一步建立准确的钢丝氢脆模型提供参考。
Finite element analysis was used to analyze the residual stress and strain of high strength pearlite steel wire drawing by finite element method. On the basis of this, finite element method was used to calculate the hydrogen diffusion concentration distribution under stress and strain induction. Hydrogen diffusion model obtained hydrogen concentration distribution of the different. The results show that due to the difference between the surface and the internal deformation rate during cold drawing, large residual tensile stress and large amount of plastic strain are produced on the steel wire after cold drawing. The existence of residual stress and strain aggravates the diffusion and aggregation of hydrogen in the material, of which the effect of strain is quite obvious. In a short period of time, due to the plastic strain decreasing the hydrogen diffusion coefficient in the material, considering the residual stress and strain, the level of hydrogen enrichment is lower than considering only the hydrogen enrichment caused by stress induction. With the increase of time, the concentration of hydrogen enrichment due to stress and strain is obviously greater than that of hydrogen concentration only when the stress is induced. Hydrogen enrichment induced by plastic strain has been confirmed by a large number of experiments. It is more practical to consider the effect of stress and strain on hydrogen diffusion and provide a reference for further establishing accurate model of hydrogen embrittlement.