In view of fine cracks occurred on the surface of BNbRE continuous casting slabs for heavy rail in the practical production, the effect of two factors, i.e. deformation temperature, deformation velocity, on thermo pla...In view of fine cracks occurred on the surface of BNbRE continuous casting slabs for heavy rail in the practical production, the effect of two factors, i.e. deformation temperature, deformation velocity, on thermo plasticity of BNbRE steel at the third brittle zone was quantitatively investigated on GLEEBLE-1500D thermal-mechanical simulator after measuring the RA-T curve of BNbRE steel. The results provide experimental data for optimizing the technology of continuous casting secondary cooling zone and avoiding the occurrence of fine surface cracks.展开更多
研究了不同固溶处理工艺对Haynes282耐热合金组织与硬度的影响。结果表明,在1060~1150℃范围内保温2 h固溶处理时,Haynes试验合金的晶粒长大缓慢,固溶温度高于1150℃时,晶粒尺寸长大明显,M23C6和MC型碳化物基本溶解。1120℃固溶处理时,...研究了不同固溶处理工艺对Haynes282耐热合金组织与硬度的影响。结果表明,在1060~1150℃范围内保温2 h固溶处理时,Haynes试验合金的晶粒长大缓慢,固溶温度高于1150℃时,晶粒尺寸长大明显,M23C6和MC型碳化物基本溶解。1120℃固溶处理时,随着保温时间的延长,晶粒长大,未溶碳化物不断溶解。计算表明,Haynes试验合金固溶处理晶粒长大激活能Q约为382 k J/mol。提高固溶处理温度和延长保温时间时,合金硬度降低,晶粒粗化和未溶碳化物的溶解是造成硬度降低的主要原因。展开更多
Repeated bending occurs toward the direction of rail head and rail base during the cooling which can lead to significant bending deformation and residual stress after cooling.The longer the rail is,the more obvious th...Repeated bending occurs toward the direction of rail head and rail base during the cooling which can lead to significant bending deformation and residual stress after cooling.The longer the rail is,the more obvious this phenomenon is.In addition to cooling function,a kind of cooling bed with a pre-bending process is used in order to solve this problem on 100 m rail.The synchronous movements on this cooling bed can be realized by the automatic control system after establishing the mathematical model of bending deformation after rolling.The rail is reversely bent toward the rail base before cooling according to the pre-bending control of the pre-bending curve and is straight after cooling,which can realize the control of the residual stress after pre-bending and straightening.The straightening residual stress is significantly reduced after the pre-bending.展开更多
基金Project supported bythe Inner Mongolian Autonomous Region Educational Department (NJ050667)
文摘In view of fine cracks occurred on the surface of BNbRE continuous casting slabs for heavy rail in the practical production, the effect of two factors, i.e. deformation temperature, deformation velocity, on thermo plasticity of BNbRE steel at the third brittle zone was quantitatively investigated on GLEEBLE-1500D thermal-mechanical simulator after measuring the RA-T curve of BNbRE steel. The results provide experimental data for optimizing the technology of continuous casting secondary cooling zone and avoiding the occurrence of fine surface cracks.
文摘研究了不同固溶处理工艺对Haynes282耐热合金组织与硬度的影响。结果表明,在1060~1150℃范围内保温2 h固溶处理时,Haynes试验合金的晶粒长大缓慢,固溶温度高于1150℃时,晶粒尺寸长大明显,M23C6和MC型碳化物基本溶解。1120℃固溶处理时,随着保温时间的延长,晶粒长大,未溶碳化物不断溶解。计算表明,Haynes试验合金固溶处理晶粒长大激活能Q约为382 k J/mol。提高固溶处理温度和延长保温时间时,合金硬度降低,晶粒粗化和未溶碳化物的溶解是造成硬度降低的主要原因。
基金the National Natural Science Foundation of China (No.50765004)
文摘Repeated bending occurs toward the direction of rail head and rail base during the cooling which can lead to significant bending deformation and residual stress after cooling.The longer the rail is,the more obvious this phenomenon is.In addition to cooling function,a kind of cooling bed with a pre-bending process is used in order to solve this problem on 100 m rail.The synchronous movements on this cooling bed can be realized by the automatic control system after establishing the mathematical model of bending deformation after rolling.The rail is reversely bent toward the rail base before cooling according to the pre-bending control of the pre-bending curve and is straight after cooling,which can realize the control of the residual stress after pre-bending and straightening.The straightening residual stress is significantly reduced after the pre-bending.
