EVALUATION OF SERVICE LIFE WELD METAL OF STEEL 15H2MFA (Т=550ОС) IN THE LONG-TERM CREEP IN STATIC LOADING

Abstract

The actual conditions of operation of various structural elements, the increase in the requirements to their life and the improvement of the methods for their calculation predetermine the necessity of taking into account a wide range of factors influencing their load-carrying capacity. Among these factors are the temperature, stress state type, mode of loading, etc. In order to assess the life of structural elements, investigations on creep in various structural elements at a complex stress state are urgent. The analysis of the earlier published studies strongly testifies that the processes of plastic deformation and fracture of materials essentially depend on the stress state type, and since the creep calculations of structural elements under conditions of complex stress state are based on the results of the experimental investigations of materials obtained at a linear complex stress state, the investigations of various structural materials in creep at a linear stress state and also the establishing of the relationship between the main characteristics in the creep and life calculations of the materials under study are of practical interest. The paper presents the deformation behavior of the weld metal of 15Kh2МFА steel (Т=550о С) under sustained static loading at a linear stress state. The regularity between the minimum creep strain rate and the time to fracture of the metal is found. The performed set of investigations will further make it possible to develop experimentally justified approaches to life assessment of metals taking into account a number of operational factors.