Method for predicting high-temperature creep property of heat resistant steel

Abstract

The invention provides a method for predicting high-temperature and long-term creep property of heat resistant steel, and is particularly suitable for prediction of the high-temperature and long-term creep property of 9-12% of Cr ferrite heat resistant steel. Strain hardening and strain softening behaviors of the materials in a high-temperature stretching process are obtained by a constant slow-speed and high-temperature tensile testing method at the strain rate which is smaller than or equal to 10-5S-1, so as to represent dislocation creep and predict the creep deformation behavior which is the same as the deformation mechanism. Thus, the long-term creep property of the material is estimated in advance. Compared with a creep test, the method is simple to operate, short in test period and high in efficiency, and can be used for primarily screening alloy ingredients when a new steel variety of the 9-12% of Cr ferrite heat resistant steel is designed. Compared with the traditional creep test assessment method, the design cycle of alloy is greatly shortened; and the development cost of the alloy is saved.

Description

technical field [0001] The invention relates to a method for predicting the performance of heat-resistant steel, in particular, the invention relates to a method for predicting the high-temperature creep performance of heat-resistant steel. Background technique [0002] For components that only allow a certain amount of deformation during long-term high-temperature operation, such as power plant boilers and steam turbines, the creep limit is an important design basis. Most specify a creep rate of 10 -5 (% / hour) is equivalent to 1% deformation for 100,000 hours. The metal materials used to manufacture such components usually have to undergo creep tests for tens of thousands of hours or even longer. [0003] Heat-resistant steel refers to alloy steel that maintains high durable strength, creep resistance and good chemical stability in high temperature environments. According to its normalizing structure, it can be divided into austenitic heat-resistant steel, martensitic hea...

AI Technical Summary

Problems solved by technology

For example, under creep conditions, the loss of outer section and the nucleation and growth of creep voids occur simultaneously. For most heat-resistant alloys, the loss of outer section and the damage of creep voids also occur at the same time as the coarsening of second phase particles. Deterioration, that is, there is a certain gap between the calculation model and the actual creep rupture microstructure, and the creep life of high-temperature materials cannot be accurately predicted

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