钢凝固过程超细钛氧化物析出的热力学分析

THERMODYNAMIC ANALYSIS OF ULTRA FINE Ti OXIDE INCLUSION PRECIPITATION DURING STEEL SOLIDIFICATION

某些类型超细钛氧化物能促进针状铁素体的形成,细化晶粒。钛氧化物夹杂的析出类型受钢液中的氧含量、合金元素成分的影响。以X80管线钢成分为研究对象,从热力学角度分析了微合金元素及钢液中的氧浓度对其析出类型的影响。结果显示,在钢液凝固温度区间,相同温度和氧含量时,Ti的氧化物中,Ti3O5是最稳定的,其次为Ti2O3。钢中铝对钛氧化物形成有显著影响,必须严格控制钢中的铝钛比。当温度为1 873 K,钢液中Ti含量为0.02%时,铝浓度要小于34μg/g。钢液中有锰存在时会影响凝固过程中析出的钛氧化物的类型。氧含量不同,氧化物的类型不同。

Some type of ultra fine Ti oxides could refine the grains by acting as heterogeneous nucleation sites of intragranular ferrite（IGF）.The type of precipitated Ti oxide was affected by oxygen content,alloying elements contents of liquid steel.A thermodynamic study of the type of precipitated oxide in X80 pipeline steel was presented.The results showed that the Al/Ti ratio should be controlled to ensure the Ti oxides precipitating during steel solidification.Ti3O5 was the most stable among all Ti oxides in the range of solidification temperature.／ content should be less than 34 μg/g when ／ content is 0.02% at 1 873 K.／ in liquid steel could affect the type of Ti oxide for given oxygen content.