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特殊钢中的合金元素主要分为强烈碳化物形成元素和稳定奥氏体元素,它们的热力学性质和对碳扩散的影响不同。合金元素增加钢的淬透性可由影响相变速率和形核的理论来解释。合金元素对淬火——回火钢性能的影响可归结于合金元素对 M_s 温度、马氏体形态、残余奥氏体量及分布以及对回火组织的变化。合金元素在铁素体中的扩散率影响回火时的二次硬化效果。微量强烈碳化物合金元素通过细化铁素体和碳化物使正火钢的强度由200～300MN·m~(-2)提高到450～500MN·M~(-2),成为正火钢发展的方向。这些极为弥散的碳化物系相界沉淀和纤维析出。以 Ti 代 V 或以 N 代 C 可使碳化物延迟粗化。
The alloying elements in special steels are mainly divided into strong carbide forming elements and stable austenitic elements, and their thermodynamic properties have different effects on carbon diffusion. Increasing the hardenability of alloying elements by the steel can be explained by the theory that affects the rate of phase transformation and nucleation. The effect of alloying elements on the properties of quenched-tempered steels can be attributed to the alloying element’s influence on the M_s temperature, the martensite morphology, the retained austenite content and distribution, and the change in tempering microstructure. Diffusion rate of alloying elements in ferrite affects the secondary hardening effect during tempering. Micro-carburizing alloying elements improve the strength of normalized steel from 200 ~ 300 MN · m -2 to 450 ~ 500 MN · M -2 by refining ferrite and carbide, and become a normalized steel. The direction of These extremely dispersive carbide-like phase boundaries precipitate and fibers are precipitated. Carbide delayed roughening with Ti on behalf of V or N on C