Cr12N钢高压凝固过程中的气泡析出行为

Bubbles Separation Behaviour of Cr12N Steel during High Pressure Solidification Process

针对冶炼Cr12N铁素体不锈钢时有气泡产生的现象。用蔡司显微镜对冶炼出的钢锭进行观察并采用图像分析软件对得到的图片进行分析处理,得到气泡的分布规律。结果表明:当熔炼压力0.6 MPa时,凝固压力由1.0MPa增加到1.6 MPa,气泡数量的平均值由46.37个/mm2降到9.46个/mm2;直径大于20μm的气泡数量下降到原来的17.4%,而直径小于5μm的气泡数量增加了37.7%;但随着凝固压力的增加,气泡面积百分比越来越小。在熔炼压力0.3 MPa凝固压力1.6 MPa条件下得到的钢锭,其下表面的气泡平均面积含量比例是上表面气泡含量的23.9%,边缘位置处的气泡平均面积含量比例是中心位置处的25.9%。

Considering the some bubbles separation during smelting Cr12 N ferritic stainless steel,the ingot had been examined by an optical microscope,and the optical image had been analysed by using a microimage analysis process software. It is found out that when the melting pressure is 0. 6 MPa and solidification pressure is increased from 1. 0 MPa to 1. 6 MPa,the average number of bubbles per square millimeter decreases from 46. 37 to 9. 46,among them the number of bubble with diameter greater than 20 μm reduces down to 17. 4% of origin number,while the number of bubble with diameter less than 5 μm increases by37. 7%. With increasing solidification pressure,the bubble area percentage becomes smaller. When the ingot is produced at a combined conditions of 0. 3 MPa melting pressure and 1. 6 MPa solidification pressure,the average bubble area percentage on lower surface is 23. 9% of that on the upper surface,and average bubble area percentage at the edge position is 25. 9% of that at the center position.