Q235B和Q345B钢板坯保护渣渣膜显微结构的对比分析简

 保护渣渣膜的矿相结构是影响其传热与润滑性能的重要因素之一，偏光显微镜下对唐钢中厚板公司Q235B和Q345B板坯保护渣渣膜的矿相结构进行了系统研究。结果表明，Q235B板坯正常渣膜的结晶矿物主要为黄长石、枪晶石和硅灰石，结晶率高达90%~95%；Q345B板坯正常渣膜的结晶矿物中却没有硅灰石生成，并且结晶率也相对较低为35%~65%。对事故渣膜的研究发现，Q235B板坯出现纵裂对应的事故渣膜的突出特点是结晶率为65%~70%，较正常渣膜偏低；而Q345B板坯出现夹渣对应的事故渣膜与正常渣膜的最大区别是枪晶石晶体大量析出，并且结晶率异常升高至95%以上。

Contrastive Analysis on Microstructure of Flux Film for Q235B and Q345B Steel

Mineralogical structure of flux film is one of the important factors influencing heat transfer and lubrication performance. So the microstructures of flux films for Q235B and Q345B steel was observed by polarization microscope. The results show that, the mineralogical phase of reasonable films for Q235B steel slab casting, of which crystal rate can reach 90% to 95%, include akermanite, cuspidine and wollastonite; the reasonable films for Q345B steel slab casting, of which the crystal rate can be only 35% to 65%, barely include wollastonite. In light of accidental films for Q235B steel slab with longitudinal cracks, the outstanding characteristic is that crystal rate can be only 65% to 70%; as to accidental films for Q345B steel slab with surface inclusions, the biggest difference comparing with reasonable films is the mass formation of cuspidine, while crystal rate can anomaly reach 95% or more.