Study of creep properties of heat resistant steels

Abstract

In industrial plant the components are subjected to severe conditions of temperature and mechanical stress, the plastic deformation that continues over time. This process, called creep, occurs in petrochemical industries, power plants, and oil refineries, where its components are used for long periods of time and exposed to severe service conditions. The objective of this thesis is to study the creep behavior of ferritic steels (1Cr 0.5Mo, 2.25 Cr 1 Mo and 5Cr 0.5 Mo), and nickel-based alloys ((Incoloy 800 (30 Ni - 20 Cr), Inconel 601 (60 Ni - 25 Cr) and steels of the HP series (25 Cr - 35 Ni) that have high thermomechanical resistance associated with the internal microstructure of the matrix. The variation of the characteristic parameters of creep, such as activation energy and coefficient of stress, related to
the deformation rate, the applied stress and the temperature; simultaneously the microstructural evolution is characterized, in the conditions of temperature and time similar to the tests. Experimentally, through creep tests, test conditions will be reproduced in the laboratory, with characteristics similar to those of in-service operation. The experimental curves obtained in this way will allow us to know the variation of the physical and mechanical properties; study the mechanisms responsible for the phenomenon and describe parameters that are related to the mechanical resistance of the material.