METHOD OF EVALUATION OF SHAPE-STABILITY OF METAL MATERIAL WORKING UNDER THERMAL LOADS

摘要

FIELD: testing equipment. SUBSTANCE: samples of material are subjected to effects of temperature. This action is performed by annealing from temperature of stress removal to 0.8 melting temperature of it, ultimate strength boundaries are recorded and serviceability of material is evaluated by presence of zone of loss of strength in which drop of ultimate strength is not less than 0.2-0.3 of initial state but not below value of margin of elastic deformation. Annealing is conducted with temperature intervals 30-50 C and endurance duration 15-20 min. Annealing temperature for internally oxidized copper alloys is chosen within 700 to 1000 C and zone of loss of strength is limited by condition of drop of value of ultimate strength not less than 0.25-0.28 of initial state but not below 50.0 kg/sq.mm. Annealing temperature for action on molybdenum and its alloys is chosen from 900 to 1300 C and zone of loss of strength is limited by condition of drop of value of ultimate strength not less than 0.20-0.25 of initial state but not below than 60.0 kg/sq.mm. EFFECT: improved authenticity of method. 4 cl, 2 dwg, 1 tbl