Stress relaxation at room temperature for sheet single-crystal molybdenum

Abstract

1. Results of stress relaxation tests by two different procedures (compensation and static) for rolled sheet single-crystal molybdenum at room temperature and with initial stresses σ0 < 0.4σ0.2 are close in value. Stress relaxation curves calculated taking account of the change in distribution of bending stresses over the specimen cross section in this region of initial stresses almost coincide with experimental curves. 2. Values of stress relaxation limit on reaching residual strain of 0.001 and 0.005% on a base of 500 h, and also the stress relaxation limit σ nom o = 70 ± 10 MPa below which relaxation does not occur, have been determined in specimens of rolled sheet single-crystal molybdenum. 3. In specimens of rolled single-crystal molybdenum tested with initial stresses of σ0 0.4σ0.2 for 500 h, 90% of the residual strain accumulates in the first 25 h.