The hot compression tests on an SPHC steel were carried out in the temperature range of 900-1150 ℃ and strain rate range of 0.1-10 s-1,in which the maximum true strain is 0.8.The activation energy of test steel was c...The hot compression tests on an SPHC steel were carried out in the temperature range of 900-1150 ℃ and strain rate range of 0.1-10 s-1,in which the maximum true strain is 0.8.The activation energy of test steel was calculated,to be 299.4 kJ/mol.The critical stresses and strains for initiation of dynamic recrystallization were determined based on changes of the work hardening rate（θ）as a function of the flow stress（σ）or strain（ε）,respectively.The dependence of the peak strain（εp）,the peak stress（σp）,and the steady state stress（σs）were determined based on the Zener-Hollomen parameter.The mathematical models of the flow stress evolution were established in the hardening and dynamic recovery region and dynamic recrystallization region,respectively.The average error between experimental curves and predicted ones was around 3.26%.展开更多
The effect of Al content in molten steel on the interaction between SPHC steel(0.005-0.068 wt.%Al,and 19×10^(-4)-58×10^(-4)wt.%O)and MgO-C refractory(11.63 wt.%C)was investigated.Non-metallic inclusions in t...The effect of Al content in molten steel on the interaction between SPHC steel(0.005-0.068 wt.%Al,and 19×10^(-4)-58×10^(-4)wt.%O)and MgO-C refractory(11.63 wt.%C)was investigated.Non-metallic inclusions in the steel were examined at various periods(0,5,15,30,45,and 60 min)as well as the MgO-C interface after 60 min of corrosion at 1600℃.The results show that when MgO-C refractory comes into contact with SPHC steel,the refractory interface consists of three layers arranged from the innermost to the outermost,including the original refractory layer,the dense MgO layer,and the iron infiltration layer.The carbon in the MgO-C refractories and the Al content in the molten steel undergo a reaction with the MgO in the refractories,resulting in an increase in Mg concentration in the steel.Increasing Al content in the molten steel from 0.005 to 0.068 wt.%causes a spinel layer to appear at the interface,and the disappearance time of Al_(2)O_(3) inclusions in the steel decreases from 60 to 30 min,while the average MgO content in inclusions increases.Therefore,controlling the Al content in the molten steel and the smelting duration can help regulate the formation of spinel inclusionsinthe steel.展开更多
基金Item Sponsored by National Natural Science Foundation of China(50675133)National Basic Research Program of China(973 Program)(2006CB705401)
文摘The hot compression tests on an SPHC steel were carried out in the temperature range of 900-1150 ℃ and strain rate range of 0.1-10 s-1,in which the maximum true strain is 0.8.The activation energy of test steel was calculated,to be 299.4 kJ/mol.The critical stresses and strains for initiation of dynamic recrystallization were determined based on changes of the work hardening rate（θ）as a function of the flow stress（σ）or strain（ε）,respectively.The dependence of the peak strain（εp）,the peak stress（σp）,and the steady state stress（σs）were determined based on the Zener-Hollomen parameter.The mathematical models of the flow stress evolution were established in the hardening and dynamic recovery region and dynamic recrystallization region,respectively.The average error between experimental curves and predicted ones was around 3.26%.
基金supported by the National Natural Science Foundation of China(51974017).
文摘The effect of Al content in molten steel on the interaction between SPHC steel(0.005-0.068 wt.%Al,and 19×10^(-4)-58×10^(-4)wt.%O)and MgO-C refractory(11.63 wt.%C)was investigated.Non-metallic inclusions in the steel were examined at various periods(0,5,15,30,45,and 60 min)as well as the MgO-C interface after 60 min of corrosion at 1600℃.The results show that when MgO-C refractory comes into contact with SPHC steel,the refractory interface consists of three layers arranged from the innermost to the outermost,including the original refractory layer,the dense MgO layer,and the iron infiltration layer.The carbon in the MgO-C refractories and the Al content in the molten steel undergo a reaction with the MgO in the refractories,resulting in an increase in Mg concentration in the steel.Increasing Al content in the molten steel from 0.005 to 0.068 wt.%causes a spinel layer to appear at the interface,and the disappearance time of Al_(2)O_(3) inclusions in the steel decreases from 60 to 30 min,while the average MgO content in inclusions increases.Therefore,controlling the Al content in the molten steel and the smelting duration can help regulate the formation of spinel inclusionsinthe steel.
