莱钢特钢厂50 t UHP-EAF(热装铁水比≥50%)+LF(VD)冶炼的Q235D钢(0.10%～0.17%C)260mm×300 mm的连铸坯轧制成直径Φ150 mm圆钢后,钢材表面出现裂纹。分析表明,钢的包晶点的碳当量[C_1]与钢中实际碳含量[C]之间的差别△C越大,亚包晶...莱钢特钢厂50 t UHP-EAF(热装铁水比≥50%)+LF(VD)冶炼的Q235D钢(0.10%～0.17%C)260mm×300 mm的连铸坯轧制成直径Φ150 mm圆钢后,钢材表面出现裂纹。分析表明,钢的包晶点的碳当量[C_1]与钢中实际碳含量[C]之间的差别△C越大,亚包晶钢Q235D钢材废品率越高。实践表明,控制0.15%～0.17%[C]使△C<0.015%,钢液过热度20～30℃,结合降低结晶器冷却水流量和二冷区冷却强度,低拉速,使成品材表面质量合格率在99.3%以上。展开更多
This study investigates the stratification of soil thermal properties induced by soil organic carbon (SOC) and its impacts on the parameterization of the thermal properties. Soil parameters were measured for alpine gr...This study investigates the stratification of soil thermal properties induced by soil organic carbon (SOC) and its impacts on the parameterization of the thermal properties. Soil parameters were measured for alpine grassland stations and North China flux stations, with a total of 34 stations and 77 soil profiles. Measured data indicate that the topsoils of alpine grasslands contain high SOC contents than underlying soil layers, which leads to higher soil porosity values and lower thermal conductivity and bulk density values in the topsoils. However, this stratification is not evident at the lowland stations due to low SOC contents. Evaluations against measured data show that three thermal conductivity schemes used in land surface models severely overestimate the values for soils with high SOC content (i.e. topsoils of alpine grassland), but they are better for soils with low SOC content. A new parameterization is then developed to take the impacts of SOC into account. The new one can well estimate the soil thermal conductivity values in both low and high SOC content cases, and therefore, it is a potential candidate of thermal conductivity scheme to be used in land surface models.展开更多
文摘莱钢特钢厂50 t UHP-EAF(热装铁水比≥50%)+LF(VD)冶炼的Q235D钢(0.10%～0.17%C)260mm×300 mm的连铸坯轧制成直径Φ150 mm圆钢后,钢材表面出现裂纹。分析表明,钢的包晶点的碳当量[C_1]与钢中实际碳含量[C]之间的差别△C越大,亚包晶钢Q235D钢材废品率越高。实践表明,控制0.15%～0.17%[C]使△C<0.015%,钢液过热度20～30℃,结合降低结晶器冷却水流量和二冷区冷却强度,低拉速,使成品材表面质量合格率在99.3%以上。
基金supported by National Natural Science Foundation of China (Grant No. 41105003)Key Project of Chinese Academy of Sciences (Grant No.KZCX2-YW-Q10-2)+1 种基金National Natural Science Foundation of China (Grant No. 91025004)Open Fund from the State Key Laboratory of Remote Sensing Science (Grant No. OFSLRSS201108) that is cosponsored by the Institute of Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal University
文摘This study investigates the stratification of soil thermal properties induced by soil organic carbon (SOC) and its impacts on the parameterization of the thermal properties. Soil parameters were measured for alpine grassland stations and North China flux stations, with a total of 34 stations and 77 soil profiles. Measured data indicate that the topsoils of alpine grasslands contain high SOC contents than underlying soil layers, which leads to higher soil porosity values and lower thermal conductivity and bulk density values in the topsoils. However, this stratification is not evident at the lowland stations due to low SOC contents. Evaluations against measured data show that three thermal conductivity schemes used in land surface models severely overestimate the values for soils with high SOC content (i.e. topsoils of alpine grassland), but they are better for soils with low SOC content. A new parameterization is then developed to take the impacts of SOC into account. The new one can well estimate the soil thermal conductivity values in both low and high SOC content cases, and therefore, it is a potential candidate of thermal conductivity scheme to be used in land surface models.
