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本文研究了形变热处理工艺对低氮和高氮的含钒低合金高强度钢的沉淀强化的影响。研究指出为了达到最大的沉淀强化效果,应该防止在奥氏体内出現形变诱发沉淀。氮化钒的形变诱发强化在900～950℃非常迅速地产生,但是碳化钒则在830～85℃的较低的轧制温度下产生形变诱发强化。已经考察了重新加热温度、轧制压下量、保温温度和时间的影响。业已表明沉淀强化程度约在化学当量比(V/C)处最大,但是在这个比值下,奥氏体中形变诱发强化也非常显著。氮化钒在奥氏体中沉淀有损于在铁素体中沉淀强化。但若能防止氮化钒在奥氏体中的沉淀,那么增加钢中含氮量可增加沉淀强化并能获得较高的屈服强度。铌表现出非常有效的細化晶粒作用虽然在适当的情况下它与钒比较能在更大程度上产生显著的沉淀强化,特别是在相同的低含量时。然而Nbc在奥氏体中很易形变诱发为沉淀,随后有损于铁素体的沉淀强化。另一方面钒很易于通过氮化钒而用以细化晶粒并且利用碳化钒产生沉淀强化。
In this paper, the effect of deformation heat treatment on the precipitation strengthening of low-nitrogen and high-nitrogen vanadium-bearing low-alloy high-strength steels was studied. Research shows that in order to achieve the maximum precipitation strengthening effect, precipitation-induced precipitation should be prevented in austenite. Deformation induced strengthening of vanadium nitride occurs very rapidly at 900-950 ° C, but vanadium carbide produces deformation-induced strengthening at a lower rolling temperature of 830-85 ° C. The effect of reheating temperature, rolling reduction, holding temperature and time has been examined. It has been shown that the degree of precipitation strengthening is about the maximum at stoichiometric ratio (V / C), but the strain-induced strengthening in austenite is also significant at this ratio. Precipitation of vanadium nitride in austenite detracts from precipitation hardening in ferrite. However, if the precipitation of vanadium nitride in austenite can be prevented, increasing the nitrogen content in the steel may increase the precipitation strengthening and obtain a higher yield strength. Niobium shows a very effective refining grain effect, although it gives a greater degree of precipitation strengthening than comparable vanadium, where appropriate, especially at the same low levels. However, Nbc is susceptible to deformation induced precipitation in austenite and subsequently to detrimental ferrite precipitation strengthening. Vanadium, on the other hand, is readily used to refine grains by vanadium nitride and precipitation strengthening with vanadium carbide.