高炭素高速度鋼系合金の凝固と熱処理硬さに及ぼす合金元素の影響 Effects of Alloying Elements on Solidification Process and Hardenability of High Carbon High Speed Steel Type Alloy
The effects of alloying elements on the solidification process of high carbon high speed steel type alloy were investigated by using a series of hypo-eutectic alloys of Fe-2% C-5% Cr-5% Mo-5.5% V-0/5% W-0/5% Co-0/5% Ni and a hyper-eutectic Fe-2.3% C-5% Cr-5% Mo-9% V-5% W-5% Co alloy. The solidification process of each alloy was investigated by thermal analysis and quenching experiments. In each hypo-eutectic alloy, crystallization proceeds in the order of primary <i>γ</i>, <i>γ</i> + MC eutectic, <i>γ</i> + M<sub>2</sub>C eutectic, while the primary MC instead of <i>γ</i> crystallizes in the hyper-eutectic alloy. The amount and distribution of each carbide are explained with the phase diagram and the redistribution of alloying elements during solidification. The hardness of quenched alloy was maximum at an austenitizing temperature between 1273 K and 1373 K since the hardness depends on both the amount and hardness of martensite, that is the carbon content of austenite. Each alloy was found to exhibit a temper hardening, Co in particular enhanced the hardness when the alloy was tempered at around 823K.
- 鋳造工学 = Journal of Japan Foundry Engineering Society
鋳造工学 = Journal of Japan Foundry Engineering Society 70(5), 309-315, 1998-05