以柔克刚—提高耐火材料抗热震性郑州大学高温材料研究所叶国田以柔克刚—提高耐火材料抗热震性•意在探讨一下这个巨大而艰难的课题•而不是为了解决什么问题•提出问题,旨在抛砖引玉•观点不一定很新颖•这些观点以前被其他人以不同的方式提过,甚至应用过题外话–研究题目•我们高温所研究生的研究题目:“加入Al粉对MgO-C砖结构和性能的影响”•结果:AP,BD,CCS,MOR,HMOR,PLC,TSR,SCR,XRD,SEM•结论:把对Al粉对以上性能、相组成、显微结构的影响进行总结•以上题目和结论有没有问题?题外话–研究题目•【药品名称】品名:维C银翘片•【功能主治】用于流行性感冒引起的发热、头痛、咳嗽、口干、咽喉疼痛。•【不良反应】尚无报道。•“加入Al粉对MgO-C砖结构和性能影响”•主要目标:对什么具体性能的影响?•结论提及:对其他性能有没有负面影响?Hasselman的热冲击理论•根据Hasselman的热冲击理论,在裂纹断裂起始处,裂纹扩展的驱动力与材料内的储存弹性能成正比。Hasselman,D.P.H.Unifiedtheoryofthermalshock,fractureinitiationandcrackpropagationinbrittleceramics.JournalofAmericaCeramicSociety,V.52,No.11,600-604,1969.热应力取决于弹性模量•热应力=E·=E··T•热膨胀系数:由材料本身的性质决定•T:取决于使用环境•为了减小,弹性模量E要相应地变小•E取决于微观结构(微裂纹,相分布等等)•微裂纹由工艺过程控制“Refractoriesselectionforsteelladles”(MarcoAntonioQuintela,FabioDuarteSantos,CelsoAnizioPessoa,JoseAnchietaDeRodrigues,VictorCarlosPandolfelli,UNITECR'05-ProceedingsoftheUnifiedInternationalTechnicalConferenceonRefractories,p380-384).以柔克刚–微裂纹通过微裂纹提高韧性钢包用耐火材料的选用MarcoAntonioQuintela,FabioDuarteSantos,CelsoAnizioPessoa,JoseAnchietaDeRodrigues,VictorCarlosPandolfelli,UNITECR'05-ProceedingsoftheUnifiedInternationalTechnicalConferenceonRefractories,p380-384“Refractoriesselectionforsteelladles”(MarcoAntonioQuintela,FabioDuarteSantos,CelsoAnizioPessoa,JoseAnchietaDeRodrigues,VictorCarlosPandolfelli,UNITECR'05-ProceedingsoftheUnifiedInternationalTechnicalConferenceonRefractories,p380-384).MgO-C钢包砖结合剂抗氧化剂MC1沥青AlMC2沥青-MC3树脂AlMC4树脂-“Refractoriesselectionforsteelladles”(MarcoAntonioQuintela,FabioDuarteSantos,CelsoAnizioPessoa,JoseAnchietaDeRodrigues,VictorCarlosPandolfelli,UNITECR'05-ProceedingsoftheUnifiedInternationalTechnicalConferenceonRefractories,p380-384).MgO–C砖的高温抗折强度高温抗折强度随着温度的变化情况“Refractoriesselectionforsteelladles”(MarcoAntonioQuintela,FabioDuarteSantos,CelsoAnizioPessoa,JoseAnchietaDeRodrigues,VictorCarlosPandolfelli,UNITECR'05-ProceedingsoftheUnifiedInternationalTechnicalConferenceonRefractories,p380-384).在1400℃的氧化气氛保温30分钟后的失碳情况和氧化指数抗氧化性“Refractoriesselectionforsteelladles”(MarcoAntonioQuintela,FabioDuarteSantos,CelsoAnizioPessoa,JoseAnchietaDeRodrigues,VictorCarlosPandolfelli,UNITECR'05-ProceedingsoftheUnifiedInternationalTechnicalConferenceonRefractories,p380-384).MgO-C砖初始碳含量(wt.%)失碳量(1400℃,wt.%)氧化指数(1400℃,%)MC1MC2MC3MC411.811.013.814.18.68.58.511.073776278MgO-C砖的抗热震性热剥落实验后试样的纵向横截面:金属渗透().抗热震性能随高温抗折强度的变化(1400˚C).“Refractoriesselectionforsteelladles”(MarcoAntonioQuintela,FabioDuarteSantos,CelsoAnizioPessoa,JoseAnchietaDeRodrigues,VictorCarlosPandolfelli,UNITECR'05-ProceedingsoftheUnifiedInternationalTechnicalConferenceonRefractories,p380-384).热冲击实验于1560C在感应炉中进行,长条试样(40mmx40mmx160mm)部分浸入钢水中,并在实验温度下保持60秒,然后在水中冷却15秒后放到空气中,这样热冷循环实验三次。并通过试样中产生的裂纹的尺寸和数量来衡量热冲击损伤的程度。抗渣性能图2MgO-C砖的相对侵蚀指标旋转炉渣实验采用(88mm;68mm)x30mmx190mm的试样在1650℃下保温6h。通过比较测试前后横截面的侵蚀比例来测试渣侵蚀的指标。“Refractoriesselectionforsteelladles”(MarcoAntonioQuintela,FabioDuarteSantos,CelsoAnizioPessoa,JoseAnchietaDeRodrigues,VictorCarlosPandolfelli,UNITECR'05-ProceedingsoftheUnifiedInternationalTechnicalConferenceonRefractories,p380-384).工业试用结果•如果,在机械强度、抗氧化性能和抗渣侵蚀性能的基础上,参照传统的材料评估方式,看一下,哪种才是最好的钢包渣线用耐火材料呢?•最好的不应该是MC2,因为它的抗渣性能同其他三种差不多,但是它的HMOR要远低于MC1和MC3。“Refractoriesselectionforsteelladles”(MarcoAntonioQuintela,FabioDuarteSantos,CelsoAnizioPessoa,JoseAnchietaDeRodrigues,VictorCarlosPandolfelli,UNITECR'05-ProceedingsoftheUnifiedInternationalTechnicalConferenceonRefractories,p380-384).但是,MC2表现出更加优良的工业试用性能。“Refractoriesselectionforsteelladles”(MarcoAntonioQuintela,FabioDuarteSantos,CelsoAnizioPessoa,JoseAnchietaDeRodrigues,VictorCarlosPandolfelli,UNITECR'05-ProceedingsoftheUnifiedInternationalTechnicalConferenceonRefractories,p380-384).工业试用结果•MC2比MC1、MC3和MC4表现出更加优良的工业试用性能。•MC2砖在工业应用上的优良的表现,主要是由于它的更加复杂的结构,而这要归结于它在高温下优良的抗渣性能和低的机械强度。•在抗渣性能和抗氧化性能被满足的情况下,更加优良的抗热震性能和低的高温强度才是最关键的性能。“Refractoriesselectionforsteelladles”(MarcoAntonioQuintela,FabioDuarteSantos,CelsoAnizioPessoa,JoseAnchietaDeRodrigues,VictorCarlosPandolfelli,UNITECR'05-ProceedingsoftheUnifiedInternationalTechnicalConferenceonRefractories,p380-384).TSR和HMOR的平衡点-微裂纹有利于TSR的提高-微裂纹不利于HMOR-TSRandHMOR的矛盾-TSRandHMOR的平衡点-HMOR多大才够用?12MPa?18MPa,24MPa?-高温所学生:下水口的HMOR从10MPa提高到20MPa“弹性技术”–微裂纹•高温下生成的(非计量)镁铝尖晶石:利用富铝尖晶石脱溶反应,与MgO生成二次尖晶石产生膨胀并导致微裂纹产生MgO•铁铝尖晶石系统:–铁铝尖晶石与方镁石膨胀系数的不同–在烧结和使用过程中镁铝尖晶石生成产生的提及膨胀而产生微裂纹周季婻,水泥窑窑衬用新型耐火原料的展望,耐火原料学术交流会论文集,开封,2009.3.29-31,p.21-26.颗粒周围裂纹的扩展-模式I颗粒周围的微细空隙XYXYXY扩展受阻裂纹前进扩展受阻颗粒周围的微细裂纹颗粒周围裂纹的扩展受阻X,Y:热膨胀系数100μm微裂纹受阻裂纹BX<YX=YX>Y微小空间微细裂纹木下人好HitoyoshiKinoshita,“SlidingNozzlePlatesandNozzlesforsteelmakingladlesandtundishes”,HTCI,Zhengzhou,November27,1008大晶粒裂纹原生裂纹晶界基体裂纹基体原生裂纹细晶粒一个颗粒颗粒周围裂纹的扩展-模式II木下人好HitoyoshiKinoshita,“SlidingNozzlePlatesandNozzlesforsteelmakingladlesandtundishes”,HTCI,Zhengzhou,November27,1008一个颗粒裂纹受阻基体裂纹扩展大尺寸晶粒小尺寸晶粒颗粒尺寸对裂纹扩展的影响木下人好HitoyoshiKinoshita,“SlidingNozzlePlatesandNozzlesforsteelmakingladlesandtundishes”,HTCI,Zhengzhou,November27,1008纳米添加剂对C结合MgO耐火材料的增强增韧V.Stein,C.G.Aneziris,U.Klippel,W.Schönwelski,E.GuéguenUNITECR’09碳结合MgO耐火材料的化学组成Batch123456789Wt%MgO97.8石墨1.1炭黑1.1树脂2.4(液态)+0.8(粉末)固化剂0.3Al---1.01.0