Effect of temperature-dependent surface heat transfer coefficient on the maximum surface stress in ceramics during quenching
Effect of temperature-dependent surface heat transfer coefficient on the maximum surface stress in ceramics during quenching
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陶瓷淬火过程中温度相关的表面传热系数对最大表面应力的影响
DOI：
10.1080/14786435.2015.1134836
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发表时间：
2016
影响因子：
1.6
通讯作者：
Zhou Z L
中科院分区：
文献类型：
--
作者：
Shao Y F;Song F;Jiang C P;Xu X H;Wei J C;Zhou Z L
本文用实测的表面传热系数thmin代替淬火时的平均值，研究了圆柱体表面最大应力σ max的差别。在200、300、400、500、600和800°C的淬火温度下，由hm（fmmax）计算的最大表面应力σ max总是小于由ha（famax）计算的最大表面应力σ max，但800°C除外，而由hm（fmmax）计算的达到最大表面应力σ max的时间总是早于由ha（famax）计算的。这与传统的σ max随毕奥数增加而增加，达到σ max的时间随毕奥数增加而减少的观点不一致.其他温度相关的性能也有一个小的影响，它们的相互比例与淬火温度的趋势。这两个最大表面应力之间的差异是由hm随温度的剧烈变化引起的，这在工程分析中需要考虑。
We study the difference in the maximum stress on a cylinder surfaceσmaxusing the measured surface heat transfer coefficienthminstead of its average valuehaduring quenching. In the quenching temperatures of 200, 300, 400, 500, 600 and 800°C, the maximum surface stressσmmaxcalculated byhmis always smaller thanσamaxcalculated byha, except in the case of 800°C; while the time to reachσmaxcalculated byhm(fmmax) is always earlier than that byha(famax). It is inconsistent with the traditional view thatσmaxincreases with increasing Biot number and the time to reachσmaxdecreases with increasing Biot number. Other temperature-dependent properties also have a small effect on the trend of their mutual ratios with quenching temperatures. Such a difference between the two maximum surface stresses is caused by the dramatic variation ofhmwith temperature, which needs to be considered in engineering analysis.