초록 열기/닫기 버튼
In oxidizing nitric acid solutions, stainless steel undergoes intergranular corrosion accompanied by graindropping and changes in the corrosion rate. For the safe operation of reprocessing plants, this mechanismshould be understood. In this study, we constructed a three-dimensional computational model using a cellularautomata method to simulate the intergranular corrosion propagation of stainless steel. The computationalmodel was constructed of three types of cells: grain (bulk), grain boundary (GB), and solutioncells. Model simulations verified the relationship between surface roughness during corrosion and dispersionof the dissolution rate of the GB. The relationship was investigated by simulation applying a constantdissolution rate and a distributed dissolution rate of the GB cells. The distribution of the dissolution rate ofthe GB cells was derived from the intergranular corrosion depth obtained by corrosion tests. The constantdissolution rate of the GB was derived from the average dissolution rate. Surface roughness calculated bythe distributed dissolution rates of the GBs of the model was greater than the constant dissolution rates ofthe GBs. The cross-sectional images obtained were comparable to the corrosion test results. These resultsindicate that the surface roughness during corrosion is associated with the distribution of the corrosion rate.
