THERMOPHYSICAL PROPERTIES OF SINTERED STEELS: EFFECT OF POROSITY
THERMOPHYSICAL PROPERTIES OF SINTERED STEELS: EFFECT OF POROSITY
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烧结钢的热物理性能：孔隙率的影响
DOI：
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
E. Specht
中科院分区：
文献类型：
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作者：
H. Danninger;C. Gierl;G. Mühlbauer;Monica Gonzalez;J. Schmidt;E. Specht
烧结钢热物理特性的可靠数据，特别是热膨胀系数 (CTE) 和导热率 (TC)，对于部件设计和热处理过程建模至关重要。关于孔隙率对这些性能的影响存在相互矛盾的观点。在目前的工作中，结果表明，对于粉末冶金 (PM) 钼预合金钢，通过热膨胀法在高达 1,000°C 的温度下测量的 CTE 在 5.97 g/cm 3 至 7.53 g/cm 3 的密度范围内几乎与孔隙率无关。此外，烧结方式也没有影响。 TC 是在相同温度范围内根据测量的热扩散率、比热和密度确定的。人们发现TC取决于孔隙率，但在技术相关的密度范围内的影响不如标准钢种中的合金元素在中低温度范围内所产生的影响明显。因此，烧结钢的热物理性能受孔隙率的影响小于成分的影响，并且其行为比通常假设的更像锻钢。
Reliable data for the thermophysical properties of sintered steels, in particular the coefficient of thermal expansion (CTE) and thermal conductivity (TC), are critical in the design of components and for modeling heat-treating processes. There are contradicting opinions about the effect of porosity on these properties. In the present work, it is shown that, for a powder metallurgy (PM) molybdenum prealloyed steel, CTE, measured by dilatometry up to 1,000°C, is virtually independent of porosity over a density range from 5.97 g/cm 3 to 7.53 g/cm 3 . Also, there is no effect of the sintering regime. TC was determined over the same temperature range based on measured thermal diffusivity, specific heat, and density. TC was found to depend on porosity, but the effect over the technically relevant density range was less pronounced than the effect exerted by alloying elements in standard steel grades in the low-to-medium temperature range. Thus, both thermophysical properties of sintered steels are less influenced by porosity than by composition, and behave more like wrought steels than is generally assumed.