论文部分内容阅读
我厂生产球铁已有五年多了,但生产中不断出现这样那样的问题,最突出的是在铸件断口上分布有疏散或密集的黑班点。开始认为是球化剂加入量不足,因此球化剂用量由1.6%逐渐上升到2.4%,当时炉前快速金相检查球化级别大都在1B~2A,可是打开第一箱的铸件,断口上就有黑斑点。而残余镁量和残余稀土量均不低于0.05%,并且往往出现严重缩松。我们学习兄弟厂的经验,进一步分析认为在有效时间内,孕育衰退要比球化衰退敏感的多,并且来得快,因此,得出结论:出现断口黑斑点并非球化剂不足,主要是孕育作用不好,孕育衰退太快所造成的。
Our factory has been producing ductile iron for more than five years, but such problems continue to emerge in production. The most prominent issue is the distribution of scattered or intensive black points on the fracture surfaces of castings. Began to think that the amount of nodulizer is not enough, so the amount of nodulizer gradually increased from 1.6% to 2.4%, when the rapid pre-furnace metallurgical examination of metallurgical grade 1B ~ 2A, but the first box to open the casting, fracture There are black spots. The amount of residual magnesium and residual rare earth are not less than 0.05%, and often appear serious shrinkage. We learn from the experience of Brother factory, further analysis that in the effective time, pregnant recession than the ball of the recession more sensitive and come faster, concluded that there is not black nodding fracture insufficiency, mainly inoculation Bad, pregnant with recession caused by too fast.