To elucidate the diffusion behavior of carbon atoms within the austenite region,the decarbonization of 72LX steel bloom was investigated.Experimental studies were performed to obtain the depth profiles of the decarbur...To elucidate the diffusion behavior of carbon atoms within the austenite region,the decarbonization of 72LX steel bloom was investigated.Experimental studies were performed to obtain the depth profiles of the decarburized layers within the temperature range of 950-1250℃.The findings show that,within a temperature range of 950-1200℃,both the depth of the decarburization layer of the grain interior(h_(in))and the depth of the decarbonization effect zone of the grain boundary(h_(b))increase concurrently with increasing holding temperatures and times and an inflection point is observed at 1200℃.By measuring the change in the sample diameter before and after the experiment,the change in the radius reduction of h_(Fe) causes by oxidation is obtained.Minimal changes are observed in h_(Fe) when the temperature is below 1050℃.As the temperature increases to 1100℃,a sudden change in h_(Fe) is observed,which corresponds to a rapid increase in oxidation.At temperatures above 1100℃,a more gradual change is observed.From the experimental results,a two-dimensional decarburization mathematical model is established and the carbon diffusion coefficients at different temperatures are obtained by simulation and regression fitting.The simulation values obtain from the carbon diffusion model matched well with the experimental values,thereby confirming the accuracy of the simulation process.展开更多
以甘肃道地大宗中药材当归、黄芪、党参干燥品为试验材料,通过筛选帐膜材料及气体置换方法,建立中药材低氧高氮仓储气体环境,并对低氧高氮仓储环境下3种中药材的虫蛀、霉变情况及主效成分保持效果进行评价。结果表明,应用0.18 mm TPU膜...以甘肃道地大宗中药材当归、黄芪、党参干燥品为试验材料,通过筛选帐膜材料及气体置换方法,建立中药材低氧高氮仓储气体环境,并对低氧高氮仓储环境下3种中药材的虫蛀、霉变情况及主效成分保持效果进行评价。结果表明,应用0.18 mm TPU膜、0.12 mm PVC膜和0.12 mm PE膜,采用排气法、负压抽洗法、循环制氮充气法均可创建出适于中药材仓储的低氧高氮气体环境。在该环境下仓储当归、黄芪和党参1 a,中药材不生虫、不发霉,有效成分含量显著高于空气仓储,保质期可延长7个月以上。展开更多
基金Funded by the National Natural Science Foundation of China(U20A20272)the Special Projects for Military-Civilian Collaborative Innovation in Science and Technology of Hebei Province(202231401010003)the Open Topic of Key Laboratory of Material Forming and Structure Property Control from University of Science and Technology Liaoning(USTLKFSY201708)。
文摘To elucidate the diffusion behavior of carbon atoms within the austenite region,the decarbonization of 72LX steel bloom was investigated.Experimental studies were performed to obtain the depth profiles of the decarburized layers within the temperature range of 950-1250℃.The findings show that,within a temperature range of 950-1200℃,both the depth of the decarburization layer of the grain interior(h_(in))and the depth of the decarbonization effect zone of the grain boundary(h_(b))increase concurrently with increasing holding temperatures and times and an inflection point is observed at 1200℃.By measuring the change in the sample diameter before and after the experiment,the change in the radius reduction of h_(Fe) causes by oxidation is obtained.Minimal changes are observed in h_(Fe) when the temperature is below 1050℃.As the temperature increases to 1100℃,a sudden change in h_(Fe) is observed,which corresponds to a rapid increase in oxidation.At temperatures above 1100℃,a more gradual change is observed.From the experimental results,a two-dimensional decarburization mathematical model is established and the carbon diffusion coefficients at different temperatures are obtained by simulation and regression fitting.The simulation values obtain from the carbon diffusion model matched well with the experimental values,thereby confirming the accuracy of the simulation process.
文摘以甘肃道地大宗中药材当归、黄芪、党参干燥品为试验材料,通过筛选帐膜材料及气体置换方法,建立中药材低氧高氮仓储气体环境,并对低氧高氮仓储环境下3种中药材的虫蛀、霉变情况及主效成分保持效果进行评价。结果表明,应用0.18 mm TPU膜、0.12 mm PVC膜和0.12 mm PE膜,采用排气法、负压抽洗法、循环制氮充气法均可创建出适于中药材仓储的低氧高氮气体环境。在该环境下仓储当归、黄芪和党参1 a,中药材不生虫、不发霉,有效成分含量显著高于空气仓储,保质期可延长7个月以上。
