论文部分内容阅读
引言中心疏松是滚珠轴承钢常见的缺陷之一,关于其形成原因,有的工作者认为是由于钢锭内的树枝状晶和晶间偏析所引起的化学成分不均匀而造成的。有的工作者认为钢液气体多,钢锭内部的体积收缩,可以使内部出现疏松。也有的观点认为,中心疏松是夹杂物浸蚀脱落的蚀坑。但他们都汲有把钢锭的结晶组织与微观特征联系起来。本次工作通过解剖钢锭、钢材的低倍、断口检验、金相、扫描电子显微镜观察,叙述了中心疏松的宏观、微观特征、形成原因及消除方法。
Introduction Loose center is one of the common defects of ball bearing steel. Some workers think it is due to the uneven chemical composition caused by dendrites and intergranular segregation in the ingot. Some workers think that the molten steel gas, the internal volume shrinkage, can make the internal appear loose. Other viewpoints are that the loose center is an etch pit where the inclusions are eroded away. However, they are all linked to the microstructure and microscopic features of ingots. This work describes the macroscopical and microscopic characteristics, causes of formation and elimination of loose loosening center by dissecting ingot, low magnification of steel, fracture inspection, metallography and scanning electron microscopy.