발간논문

Home > KJMM 논문 > 발간논문

Vol.12, No.2, 154 ~ 164, 1974
Title
Effects of Mischmetal on the Precipitation Hardening of the 18Ni300 Grade Maraging Steel
박원구 Won Koo Park
Abstract
The effects of mischmetal addition from 0.02% to 0.08% on the mechanical properties of 18 Ni 300 grade maraging steel were investigated. DTA and electrical resistivity measurements at a constant heating rate showed singular points and aging treatments were performed at these singular temperatures. Mechanical properties of the maraging steels were examined according to the aging treatment. Also the precipitates were investigated by the thin film electron microscope technique. It was found that 18 Ni 300 grade managing steel maintains its strength by an addition of mischmetal even after a prolonged aging treatment at temperatures below 482℃. Over-aging is not particularly detrimental to its mechanical properties. The coherency of the thin plate-like precipitates is maintained during the aging treatment for 160 hr at 482℃. Their orientations with respect to matrix are (011)α//(001)pp, [100]α//[100]pp, [01￣1]α//[010]pp or occasionally {112}α//{001}pp. The reason for such an unsual behavior is believed due to the fact that mischmetal inhibits the coarsening of precipitates by decreasing the diffusion rate of Ni and Mo forming orthorhombic Ni₃Mo.
Key Words
| PDF
대한금속∙재료학회 │ (06633) 서울시 서초구 서초대로 56길 38 대한금속∙재료학회 회관 (서초1동 1666-12번지)
Tel : 070-4266-1646 │ FAX : 02-557-1080 │ E-mail : metal@kim.or.kr
Copyright ⓒ 2013 사단법인 대한금속∙재료학회 All rights reserved.