On the Ar″ Transformation of High-C and High-Cr Steel by the Direct-Vision Equipment of Magnetization Curve

DOI Web Site Web Site

Bibliographic Information

Other Title
  • 磁化曲線直視装置による高炭素高クロム鋼のAr″変態に関する研究
  • ジカ キョクセン チョクシ ソウチ ニ ヨル コウタンソ コウクロム コウ ノ Ar ヘンタイ ニ カンスル ケンキュウ
  • On the Ar″ Transformation of High-C and High-Cr Steel by the Direct-Vision Equipment of Magnetization Curve

Search this article

Abstract

Applying “the direct-vision equipment of magnetization curve” possessing the simple integrating circuit, we are able to observe the magnetization curves of materials instantaneously on the screen of cathode-ray oscilloscope. So, we succeeded in making continuous observation of the changes in magnetization curves of steel during the process of heat treatment by using this equipment. In this paper self-hardening high-C and high-Cr steels were used as specimens, and the variations of their various magnetic elements with Ar″ transformation by quenching and tempering were observed, as follows: (1) The tendency of increase of coercive force during the course of Ar″ transformation differs from the tendency of increase of saturation and residual induction, in that the increase of coercive force is great at the commencement of the transformation and its value becomes quickly constant. (2) The relation between residual induction Br and coercive force Hc with Ar″ transformation by quenching is given in the following experimental formula: Hc=a[1−exp(−bBr)], but in this formula a and b are constant values which are determined by the kinds of steel. (3) The main reason for the increase of coercive force during Ar″ transformation lies in the fineness of martensite particles, and cannot be considered as being attributable to the precipitation of carbides and the increase of internal stresses.

Journal

Keywords

Details 詳細情報について

Report a problem

Back to top