Analysis of the formation conditions and characteristics of interphase and random vanadium precipitation in a low-carbon steel during isothermal heat treatment

作     者：Sayed Ghafar Hashemi B.Eghbali 

作者机构：Department of Materials Engineering Sahand University of Technology 

出 版 物：《International Journal of Minerals,Metallurgy and Materials》 (矿物冶金与材料学报（英文版）)

年 卷 期：2018年第25卷第3期

页      面：339-349页

核心收录：

学科分类：0806[工学-冶金工程] 08[工学] 

基　　金：One of the authors (Sayed Ghafar Hashemi) wants to express his heartfelt appreciation to Mr. G. Etzlstorfer from the Voestalpine Steel Division and Dr. M. Alaei  for pro-viding the opportunity to conduct experiments in Graz  Austria. This research did not receive any specific grant from funding agencies in the public  commercial  or not-for-profit sectors 

主　　题：low carbon steel vanadium carbide precipitation heat treatment microhardness 

摘      要：The characteristics of nanosized precipitates in steels depend on the heat-treatment parameters. The effects of characteristics of vanadium precipitates formed during isothermal heat treatment on the hardness of the ferrite matrix in low-carbon vanadium-alloyed steel were investigated through analysis of transmission electron microscopy images and microhardness measurements. The results show that, during isothermal holding in the temperature range from 675 to 750℃, only interphase precipitation occurs, whereas only random precipitation occurs in the ferrite matrix during holding at 600℃. Furthermore, during isothermal heat treatment between 600 and 675℃, both random and interphase precipitates occurred in the ferrite. Nanoscale vanadium carbides with different atomic ratios of vanadium(V) and carbon(C) were the dominant precipitates in the random and interphase precipitates. The sizes of random precipitation carbides were smaller than those of interphase ones. Also, the sample isothermally heat treated at 650℃ for 900s exhibited a higher hardness with a narrower hardness distribution.