应用连续统力学、金属物理宏观性能与固体物理微观理论, 通过推导获得了碳钢和压力容器钢线膨胀系数与宽范围温度之间的解析表达式和近似计算展开式; 提出了线膨胀系数的转捩温度Tc的定义式, 当温度低于Tc时, 线膨胀系数随温度升高而增大; 当温度高于Tc时, 线膨胀系数则随着温度升高而减小; 基于固体物理原子理论, 推导出了考虑高温热激活能诱导位错变形效应的弹性模量与温度之间的关系式,并给出了碳钢和压力容器钢弹性模量随温度变化的普适函数表达式; 对于纯铁、碳钢和压力容器钢的弹性常数, 采用导出公式的计算结果与试验结果符合甚好。

The analytical expressions and approximation expansion in series of the coefficient of linear expansion versus a wide range of temperature for carbon steel and pressure vessel steels were deduced based on the continum mechanics,mechanical properties of metals and microscopic theory of solid physics. A concept and definition of transition temperature Tc of linear expansion coefficient was firstly proposed. when the temperature was lower than Tc, the linear expansion coefficient increased with the increace of temperature, When lower than Tc it decreased with the increase of temperature. From a view of atomic theory of solid physics, the relationship between elastic modulus and temperature was deduced including the crystal dislocation resulted from the plastic deformations induced by thermal activation energy at high temperatures. The universal function expression for elastic modulus vs temperature for carbon steel and pressure vessel steels was obtained. The computed results by the above-mentioned formula agreed well with the experimental data.