CSP工艺钛微合金钢中的碳氮化钛析出相

来源期刊：钢铁2010年第2期

论文作者：娄艳芝 柳得橹 毛新平 柏明卓

文章页码：70 - 73

关键词：薄板坯连铸连轧； 钛微合金钢； 碳氮化物； 相间沉淀

Key words：CSP process； Ti-microalloyed steel； carbonitride； interphase precipitation

摘    要：应用TEM、HREM、X射线衍射等方法分析了薄板坯连铸连轧EAF-CSP工艺生产的钛微合金钢热轧板的含钛析出相,钢的化学成分(质量分数,%)为:C 0.04~0.07、Si≤0.6、Mn≤0.6、Ti 0.06~0.14。结果表明:试验钢中存在不同碳氮比的碳氮化钛,其C/N比值之差是由各析出相的形成温度及析出时钛和氮、碳在钢中的过饱和度不同造成的。试验钢萃取粉末的质量分数约占钢的0.305%。其中70%以上为渗碳体,其余的主要是钛的碳化物、氮化物和碳氮化物以及少量硫化物和氧化物。添加钛明显增加了细小析出相的数量。在CSP工艺连铸坯及热轧板中均观察到由相间沉淀方式形成的碳氮化物粒子列。讨论了相间沉淀的形成机制。

Abstract: Hot strips of Ti-microalloyed steels(containing C 0.04%-0.07%,Si≤0.6%,Mn≤0.6%,Ti 0.06%-0.14%) produced by EAF-CSP(Electric Arc Furnaces-Compact Strip Production) process were examined by TEM,HREM and XRD.Titanium carbonitrides with different C/N ratio were found in the samples.The varying composition of the Ti-carbonitrides is resulted from the supersaturation of Ti,N and C in the steel and the temperature at which the compound forms.The results show that mass fraction of the extracted powder is about 0.305% in total.Among them more than 70% are cementite,the remains are mainly titanium carbonitrides,carbides,nitrides and a little of sulfides and oxides.Particle arrays formed through the interphase precipitation are observed either in the slabs or in the strips.The dominating reaction mechanism is discussed.Compared with the conventional cold charge process,small addition of Ti is more effective for the precipitation of fine precipitates in the steels produced by CSP process.