Material cyclic hardening behavior testing method in welding process

Abstract

The invention relates to a material cyclic hardening behavior testing method in welding process. The testing method comprises the following steps: 1) mounting a test sample on a high-temperature fatigue testing machine, heating the test sample to set temperature in a certain heating speed by using an annular infrared heating furnace, and preserving the heat of the test sample; 2) performing multi-stage load cyclic tensile-compression test by adopting strain control; 3) drawing a stress-strain curve graph of the cyclic tensile-compressive test, establishing a relation of the maximum tensile stress and cyclic number under the set temperature, and determining a strain hardening characteristic based on the maximum tensile stress change tendency; 4) computing the relative internal stress according to the cyclic stress-strain curve of the cyclic tensile-compressive test; and 5) taking a relative internal stress mean of the temperature under a test sample material mechanics melting point as the proportion of the test sample material follow-up hardening model according to the relation curve of the relative internal stress and the test temperature. Compared with the prior art, the testing method disclosed by the invention has the advantages of qualitatively evaluating the cyclic hardening characteristic and quantitatively determining the proportion of the follow-up hardening model.

Description

technical field [0001] The invention relates to the field of welding mechanics, in particular to a method for testing the cyclic hardening behavior of materials during welding. Background technique [0002] Due to the inhomogeneous microstructure and mechanical properties of welded joints caused by the welding thermal cycle, welding deformation and residual stress will inevitably occur. Comprehensive and accurate evaluation of welding residual stress has an important impact on the life prediction and integrity evaluation of welded structures. It is the development trend of today's information age to change the research mode from "theory-test-production" to "theory-computer simulation-production" by combining scientific numerical simulation technology with a small amount of experimental verification. In new product design , Process development and optimization, structural safety assessment and failure analysis provide important support, which not only saves a lot of manpower ...

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Problems solved by technology

However, this method only predicts the fatigue life, and does not predict the stress-strain relationship under multi-level fatigue loads.

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