【摘要】 同种成分下，研究了在不同加入量的氮化锰下阶梯试块铸件各个台面的硬度及应力。根据试验结果分析可知：同等情况下（无激冷冷铁），通过添加氮化锰形成动力学过冷能有效提高阶梯试块台面的硬度；40～80 mm薄壁硬度值提升50～70 HBW;100～200 mm厚壁硬度值提升20～40 HBW；薄壁较厚壁处硬度会先达峰值；氮化锰在随流孕育的条件下改善了阶梯试块铸件断面的应力均匀性，减小了阶梯断面的应力差距，使应力分布更趋均匀。更多还原

【Abstract】 Under the same composition,the hardness and stress of each step surface in the stepped test block castings were studied with varying amounts of manganese nitride added.Based on the experimental results,the following conclusions were drawn:Under identical conditions(without chill cooling),the addition of manganese nitride forms kinetic undercooling,effectively increasing the hardness of the stepped test block surfaces.For thin walls( 40～80 mm),the hardness improved by50～70 HBW;for thick walls(100～200 mm),the hardness improved by 20～40 HBW.The hardness of thin walls reaches the peak earlier than that of thick walls.Under the condition of metal stream inoculation,manganese nitride improves the stress uniformity of the cross-section of the stepped test block,reduces the stress difference between the stepped section,and makes a more homogeneous stress distribution.更多还原