论文部分内容阅读
将实验V-Nb-Mo微合金钢在1200℃固溶处理,在500℃回火不同时间,用场离子显微镜(FIM)研究实验钢中碳化物的析出过程。结果表明:回火0.5 h的样品中,碳化物处于形核长大时期,与基体的{110}呈共格关系;随着回火时间的延长,碳化物形成独立的晶体结构,与基体{110}之间呈半共格关系;回火100 h后,碳化物粗化长大,与基体呈非共格关系;形状系数随着回火时间的延长先变大再变小,析出相尺寸从1.6 nm逐渐增大至15 nm。500℃回火30 h的实验钢力学性能最佳,表明碳化物的析出强化效果最明显,相应的碳化物尺寸约为4 nm。
The experimental V-Nb-Mo microalloyed steel was solution treated at 1200 ℃ and tempered at 500 ℃ for different time. The precipitation of carbides in the experimental steel was studied by field ion microscope (FIM). The results show that the carbides form a coherent relationship with the {110} matrix during the nucleation and growth of the samples after tempering for 0.5 h. The carbide forms an independent crystal structure with the extension of tempering time, 110}. After tempering for 100 h, the carbides coarsen and grow up, which is non-coherent with the matrix. The shape factor increases first and then decreases again with the extension of the tempering time. The size of precipitated phase Increasing from 1.6 nm to 15 nm. The mechanical properties of the experimental steel tempered at 500 ℃ for 30 h were the best, indicating the most obvious precipitation strengthening effect of carbide, the corresponding carbide size is about 4 nm.