METHOD FOR ESTIMATING THERMAL FATIGUE LIFE OF METAL MATERIAL

• Main Authors: KIMURA HIROFUMI, OTSUKA KIMITERU
• Format: Patent
• Language: English
• Published: 18.05.1992
• Subjects: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; MEASURING; PHYSICS; TESTING

PURPOSE:To measure the lives of a different kind of materials within a short time by calculating the thermal fatigue lives of two or kinds of materials of the same main component type and the energy loss of a test and using the relational approximate expression of the value calculated by dividing the proof stress calculated with the same material test piece by the calculated energy loss and the calculated thermal fatigue life. CONSTITUTION:Energy loss is the area of stress-strain hysteresis in a certain cycle and proof stress is calculated by the tensile test on the same material as a thermal fatigue test material. The proof stresses and energy losses of four kinds of respective ferrous materials A, B, C, D are used to calculate proof stress/energy loss P and the relation between the proof stress/energy loss P and respective thermal fatigues Nf are plotted to obtained to obtained a drawing and the relational expression thereof calculated by the method of least squares is Nf=201 X P - 45. The proof stress and thermal fatigue test of a material whose thermal fatigue life must be estimate is conducted over several cycles to calculate energy loss and the thermal fatigue life of the material is estimated using the relational expression. By this method, the thermal fatigue lives of a defferent kind of materials can be measured within a short time.