锯片基体用50Mn2V钢淬透性不良原因分析

摘要

The 50Mn2V steel supplied by a steel-making plant for saw blade matrix had poor hardenability, such as non-uniform hardness and large deformation, after being quenched. The reason of bad hardenability for the 50Mn2V steel was analysed by chemical composition analysis and microstructure observation. The results show that the bad hardenability of the 50Mn2V steel was because of the microstructure defects in the supplying sheets including obvious banded microstructure, net ferrite and bulky pearlite microstructure, and the defects were resulted from the abnormal continous casting process. The hardenability of the 50Mn2V steel could be improved by optimizing the corresponding continous casting parameters, such as liquid super-heating extent, the secondary cooling degree and the uniformity of cooling water.%某厂生产的锯片基体用50Mn2V钢经淬火后，出现硬度不均匀、变形量大等淬透性不良的现象，通过化学成分分析和显微组织观察，对其淬透性不良的原因进行了分析。结果表明：50Mn2V钢淬透性不良的主要原因在于供货钢板中存在明显的带状组织、网状铁素体组织、大块团状珠光体组织等，这些不良组织缺陷是由于连铸工艺出现异常而产生的；通过优化连铸浇注时的过热度、连铸二次冷却强度和冷却水的均匀程度可使50Mn2V钢的淬透性得到改善。