Effect of Cyclic Transformation Treatments on the Structure and Mechanical Properties of Steels.
Abstract
Cyclic transformation of 4340 steel was employed to evaluate the structural changes and strengthening efficiency of this method of heat treatment. Section sizes up to one-half inch thick were evaluated. The results show a direct relation of austenite grain size and martensite lath size into the micron range. Composite structures with hard surfaces and soft cores can be obtained in one-half inch sections. Conversely, fully hardened structures can be obtained in one-half inch sections by controlling the cycling temperature. The efficiency of the cyclic strengthening treatment is determined by the grain size established as a result of the melting practice. Grain size or subgrain size is a more sensitive indicator of strength than imperfection structure. Yield strengths up to 350,000 psi were achieved in a 4340 steel by a ten percent rolling reduction of a cyclically produces martensite structure. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1972
- Accession Number
- AD0756240
Entities
People
- K. Kreder
- L. Kaufman
- S. A. Kulin