On the Spring Properties of Inconel X Type Alloy
1966 Volume 52 Issue 5 Pages 854-868
Details
1966 Volume 52 Issue 5 Pages 854-868
Authors have reported in the preceding study, as part of a study on super alloys for springs, on the spring properties of Refractaloy 26 type alloy. This time, they investigated the spring properties at the room temperature and elevated temperature of Inconel X type alloy. This alloy was treated under various combinations of solution temperature, solution time, aging temperature, aging time and cold reduction before aging.
Characteristics at the room temperature were determined by hardness, tensile, grain size or deflection tests to confirm the spring properties. Spring properties at the elevated temperature were investigated using coil springs subjected to an optimum solution treatment, aging treatment, and cold working. Compression coil springs were manufactured for this investigation and heated from room temperature, with the temperature and deflection registered, then the modulus of rigidity and proportional limit in twisting at high temperature determined. To confirm the stability of deflection under load and heating, coil springs were heated and cooled cyclically. Also the micro-structure and the process of precipitation were observed with the help of electron-microscope.
Results obtained were as follows;
1) A combination of 982°C (solution treatment) and 704°C × 9-44 hr (aging treatment) develops better mechanical properties at room temperature than any other combination.
2) Maximum mechanical properties at room temperature, under a combination of cold working and aging treatment, can be obtained with lower aging temperature and shorter aging time.
3) The aging treatment and cold working do not affect the modulus of rigidity.
4) The proportional limit in twisting is influenced by the aging temperature, aging time and cold working. It hardly goes down up to about 600°C.
5) Permissible stress for this alloy is up to about 40kg/mm2 for one strengthened by cold working and aging treatment, when the upper temperature of reversed cyclic heating is about 400°C.
