Forecasting method of inner and outer wall temperature difference of 9% Cr martensitic steel thick wall pipeline in heat treatment

Abstract

The invention relates to a forecasting method of inner and outer wall temperature difference of a 9% Cr martensitic steel thick wall pipeline in heat treatment. The method comprises the following steps of: calculating to obtain inner and outer wall temperature difference data of T groups of pipelines with different dimensions in postweld heat treatment under the conditions of different heating widths, different temperature preservation widths, and different heat treatment environment temperatures and different temperature control temperatures; establishing a neural network based on an error back propagation by comprehensively considering the influence of the pipeline dimensions, the heating widths, the temperature preservation widths, the heat treatment environment temperatures and the temperature control temperatures on the inner and outer temperature difference in postweld heat treatment and training and testing the neural network; and finally, amending by combining the actual tested data to obtain a method for forecasting the inner and outer wall temperature difference of the 9% Cr novel martensitic heat-resistant steel thick wall pipeline in postweld heat treatment. The forecasting method can rapidly calculate the inner and outer wall temperature difference, can help for instructing and optimizing the heat treatment technology, and can improve the heat treatment quality.

Description

technical field [0001] Prediction method of temperature difference between inner and outer walls of 9%Cr martensitic steel thick-walled pipes during heat treatment. Background technique [0002] 9%Cr new martensitic heat-resistant steel mainly includes three new martensitic heat-resistant steels: T / P92, T / P91 and E911, which are widely used in ultra-supercritical boiler main steam pipes, headers and other thick-walled pipes and other components , low weld toughness is a major problem in the installation process of this series of steel pipeline welds. In order to improve the toughness of the weld, local heat treatment must be carried out on the weld. Research at home and abroad shows that the post-weld heat treatment temperature has a great influence on the weld. Treatment, the impact energy of the weld can reach more than 41J. When heating at about 740°C, the constant temperature time must be extended to achieve this index. When the heating temperature is below 730°C, ext...

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Problems solved by technology

[0007] Another object of the present invention is to solve the existing problems of the prior art; provide a 9%Cr martensite that solves the waste of time and energy in engineering by using experimental methods to measure the temperature difference between the inner and outer walls, increases costs and does not have universal applicability in experiments Prediction method of temperature difference between inner and outer walls of steel thick-walled pipes during heat treatment

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