材料期刊网

研究了在蠕变过程中有相变发生的情况下,应用通过蠕变激活能提高温度、缩短蠕变试验时间的方法的可能性。为此,用三种耐热钢和一种铝合金分别在同一应力不同温度下,进行了一系列的蠕变试验.在蠕变试验前,对试样进行了适当的热处理,使得在蠕变试验温度下有预期的相变发生.实验结果指出,在试验温度范围内,其中两种试样存在恒定的”蠕变激活能”,另两种试样则不存在恒定的“蠕变激活能”.而在有意使得上述相变不发生的情况下,这四种试样在同样的试验温度范围内,都存在恒定的蠕变激活能.这说明“蠕变激活能”不仅决定于材料的成份,而且决定于组织结构.初步分析指出,在蠕变过程中有相变发生的情况下,这种外推方法能否适用决定于相变的类型。

In order to study whether the extrapolation method of creep test by an elevation of temperature through activation energy described in a previous paper is applicable whenphase transformations occur during creep,creep tests were made on four different alloys(three heat-resisting steels and one aluminium alloy)at different temperatures with cons-tant stress.Before the creep tests,specimens were so treated that appropriate phasetransformations were expected to occur under the temperatures of tests.The experi-mental results showed that,in the temperature range investigated,there existed a cons-tant“activation energy of creep”for two alloys,but not for the other two.When phasetransformations mentioned above were made negligible,a constant activation energy ofcreep was always obtained in the same temperature range for all alloys.This indicates that,the so called“activation energy of creep”depends not only uponthe composition of material,but also upon the microstructure.A preliminary analysis shows tha,when phase transformations occur during creep,the applicability of this extrapolation method depends upon the type of phase trans-formation taken place.