Effect of Prior Cold Work on the High-Temperature Properties of a Chromium-Molybdenum Steel
Abstract
The effect of cold work on the high-temperature properties of a quenched and tempered chromium-molybdenum steel was investigated by means of stress-rupture and relaxation tests. The material with several levels of cold reduction (0, 8, 15, and 39 percent of cross-sectional area) was tested in stress-rupture at 700 deg, 800 deg, 900 deg, and 1000 deg F (370 deg, 425 deg, 480 deg, and 540 deg C) in the stress range of 45,000 to 128,000 psi, and in relaxation at 900 deg F (480 deg C) and 80 ,000 psi initial stress. The rupture and creep strengths of the steel at 700 deg F (370 deg C) was greatly enhanced by cold work, the improvement increasing with larger amounts of cold work. At 800 deg and 900 deg F (425 deg and 480 deg C) the rupture and creep strengths were generally lowered by critical amounts of cold deformation (8 to 15 percent), while beyond the critical values increased strengths were obtained. An explanation for this behavior is given in terms of the Bauschinger effect. There was no apparent influence of prior deformation on rupture strength at 1000 deg F (540 deg C); however, creep strength decreased generally with increasing prior deformation. In relaxation at 900 deg F ( 480 deg C} residual stress was lowered by an increase in cold work.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 03, 1955
- Accession Number
- AD1222145
Entities
People
- Paul Shahinian
Organizations
- United States Naval Research Laboratory