关于在低碳钢中添加微量铌的强化机构,有的认为是铁素体中凝聚的NbC的析出硬化,有的认为是铌引起的固溶体硬化、铁素体晶粒细化等等。作者研究了铌对热加工状态、正火状态和淬火回火状态下钢的强化机构的影响,旨在明确铌的强化机构。试样是采用高纯度原料用真空熔炼铸锭法炼得的。试 Some of the strengthening mechanisms for adding a small amount of niobium to low carbon steel are considered to be precipitation hardening of NbC aggregated in ferrite, and some are considered to be solid solution hardening due to niobium, refinement of ferrite grains and the like. The authors studied the effect of niobium on the strengthening mechanisms of steels in the hot working condition, the normalizing condition and the quenching and tempering condition in order to clarify the strengthening mechanism of niobium. The sample is made of high purity raw materials by vacuum melting ingot refining method. test