【摘要】 从固溶强化、析出强化和细晶强化三个方面对微合金化3.5Ni钢的强化机理进行了分析研究,同时计算了三种强化方式对强度的贡献。结果表明:3.5Ni钢进行Nb,Ti微合金化后,通过适当的工艺控制,钢中可以析出较多均匀细小的Nb(C,N),NbTi(C,N)球形颗粒和Ti N方形颗粒。这些细小粒子一方面产生析出强化的效果;另一方面钉扎奥氏体晶界,阻止晶粒长大,从而产生强烈的细晶强化效果。强度的理论计算值和实测值非常接近,同时,与国家标准CCS1996《钢质海船入级与建造规范》中的要求相比,有超过20%的余量。更多还原

【Abstract】 Strengthening mechanisms of microalloyed 3.5Ni steel were analyzed from the solution strengthening,precipitation strengthening and fine-grain strengthening.Their contribution to strengthening was also calculated.Results show that a lot of fine equaixed particles Nb(C,N),NbTi(C,N) and square particles TiN are uniformly precipitated in the matrix.These fine particles have precipitation strengthening effect and pinning effect on austenite grain boundaries,which hinder the growth of austenite grains.The calculated strength is in good agreement with the measured one.The strength of the tested steel is satisfied with National Standard CCS 1996 "Steel Seacraft Entering Level and Construction Standard" and has a surpass of 20%.更多还原