几乎所有退火的缺点(由於过热所产生的片状珠光体,不均匀的粗珠光体以及碳化物纲)都不能用重行退火得到有效的改正。这类钢中的粗大碳化物,在重行退火时不但得不到减小,相反地会剧烈增大,致使组织更加不均匀。碳化物纲同样也不能消除。 为了改变这种组织,就必须进行正常化,然後 Almost all of the shortcomings of annealing (lamellar pearlite, non-uniform coarse pearlite and carbides due to overheating) can not be effectively corrected by re-line annealing. The coarse carbides in such steels not only fail to decrease during rework annealing, but rather increase drastically, resulting in more uneven microstructure. Carbide also can not be eliminated. In order to change this organization, it must be normalized, and then