Ar-CO-CO_(2)气氛下铁碳合金薄带气固反应脱碳动力学研究

Kinetics of Fe-C Alloy Sheets During Gas-Solid Decarbonization in Ar-CO-CO_(2)

近年来,一种固态炼钢的全新工艺受到了广泛关注,该工艺采用铁水直接固化再经氧化性气氛脱除固态金属中的碳,以达到炼钢的目的,可大幅缩短薄板钢带生产流程,降低钢中夹杂物。本工作以不同厚度铁碳合金薄带为研究对象,探讨不同温度下Ar-CO-CO_(2)中气固脱碳动力学随高温气固反应脱碳的机理。研究结果表明:碳向反应界面的扩散是脱碳反应中的限制环节,脱碳温度的升高和脱碳时间的延长均有利于脱碳;在相同条件下,铁碳合金薄带厚度越薄,脱碳速率越快;2 mm厚的铁碳合金薄带的脱碳速率常数与脱碳温度的关系可近似表示为:k=-0.144+1.183×10^(-4)T;在CO-CO_(2)气氛下,铁碳合金薄带脱碳反应近似为一级反应,脱碳反应的表观活化能E_(a)=124.7 kJ/mol。

In recent years,a new solid-state steelmaking process has attracted extensive attention,and this process makes pig iron directly casted and then decarburized in an oxidizing atmosphere for steelmaking.This scheme can significantly shorten the production process of thin strips and reduce inclusions in the steel.This research based on the Fe-C alloy sheets of different thickness as the foundation exploreed the kinetics of gas-solid decarbonization in Ar-CO-CO_(2)at different temperature following high temperature gas-solid reaction decarburization mechanism.The results showed that the diffusion of carbon to the reaction interface was the restricted link for the decarburization reaction,with the increase of the decarburization temperature and holding,the content of decarburization improving.The decarburization rate was also improved by reducing the thickness of Fe-C alloy sheets under the same condition.The relationship between decarburization rate and decarburization temperature of 2 mm Fe-C alloy sheets can be approximately expressed as k=-0.144+1.183×10^(-4)T.The results illustrated that the solid phase decarburization reaction can be approximate to the first-order reaction in Ar-CO-CO_(2),and the apparent activation energy of the whole decarburization reaction(E_(a))was 124.7 kJ/mol.