【摘要】 研究了德国DIN2 0MnCr5齿轮钢锭急冷层的相变 ,测定了临界点和CCT图 发现急冷层形成时 ,高温δ 铁素体在包晶转变时有剩余 ,其周围包着奥氏体 在钢锭快冷和再加热过程中有独特的组织转变过程和形态 这种组织易于在相变应力下产生显微裂纹 ,在宏观内应力作用下可能促发钢锭红送裂纹更多还原

【Abstract】 Phase transformation of chill layer of steel DIN20MnCr5 ingot was studied and critical points and CCT diagram were also measured.When the chill layer is taking shape,there are some residuary δ ferrite surrounded by austenite after the peritectic change.Special structural transformation occurs in quick cooling and reheating process and it formed an unusual structure in which microcracks are produced easily under structural stress.The hot charging cracks are possibly caused by the action of macro stress.更多还原