Aging effect on hardness, elasticity modulus and natural frequency of 304 stainless steel (304 SS)

The hardening behavior, natural frequency and mechanical properties of 304 austenite stainless steel after aging heat treatment were investigated. Carbide phase precipitation nucleates at austenite and becomes more intense with the increase of time and temperature. Carbides cause severe sensitization in specimens aged at 750 °C, 850 °C and 950 °C for 72 hours. With increasing structuralchanges, it was found that the natural frequencies of the five modulus increase significantly. Mechanical properties were evaluated at room temperature for all the heat-treated samples. A reasonable increase in elasticity modulus and hardening was observed after aging. These promising results are the elaboration of a nondestructive new method for estimating the remaining life for components of different generations under long-term overheated operation conditions.

Keywords:

Aging , 304 Stainless steel , Hardening , Microstructural changes , Natural Frequency