高クロム白鋳鉄の高温圧縮強さ High Temperature Compressive Strength of High Chromium White Cast Irons
Unidirectional solidification of hypo-eutectic, eutectic and hyper-eutectic high chromium cast irons was conducted to make clear the deformation behavior of the irons at elevated temperatures. The relation between the microstructure and the high temperature strength was studied at the temperatures up to 1073K. The volume fraction of precipitated carbide in the iron depends strongly on its chemical composition. The eutectic iron shows the highest strength in the whole temperature range. Strain rate sensitivity exponent (<i>m</i>) at the temperatures above 873K is approximately 0.1, even though the volume fraction of carbide changes from 20 to 45 vol % in the irons. The eutectic iron shows about the same hardness and higher compressive strength compared with the hyper-eutectic iron in spite of much smaller volume fraction of carbide than that in the hyper-eutectic iron. The hypo-eutectic iron shows a large amount of plastic deformation, while the eutectic and hyper-eutectic irons show very small plastic strain during deformation due to more brittle carbides. Therefore, the deformation behavior is different in each iron. The rule of mixtures holds for the hypo-eutectic and eutectic irons but does not for the hyper-eutectic iron.
- 鋳造工学 = Journal of Japan Foundry Engineering Society
鋳造工学 = Journal of Japan Foundry Engineering Society 70(11), 793-799, 1998-11