Test system for extension of multi-axis and salt-spray corrosion fatigue crack

Abstract

The invention relates to a test system for the extension of a multi-axis and salt-spray corrosion fatigue crack. The test system comprises a fatigue tester for providing I-type, II-type, III-type and compound fatigue loads required by a test for a test sample through a pull-cut-twist multi-axis loading fixture, and further comprises a salt-spray corrosion environmental box, wherein the salt-spray corrosion environmental box comprises a salt-spray corrosion box body and a salt-spray pre-occurrence box body which are mutually communicated through a pipeline; the salt-spray pre-occurrence box body conveys air and salt water required by salt-spray forming to the salt-spray corrosion box body; the salt-spray corrosion box body provides a required salt-spray corrosion environment for the fatigue crack extension test; both the pull-cut-twist multi-axis loading fixture and the fatigue crack extension test sample are positioned in the salt-spray corrosion box body. Through the adoption of the test system, the fatigue crack extension rate and other fracture mechanics parameters under the combined action of multi-axis loads and the salt-spray corrosion environment can be measured relatively well, and thus the material selection design and the service life evaluation for marine engineering equipment serving in the salt-spray corrosion environment and under a complex stress state can be supported.

Description

technical field [0001] The invention belongs to the technical field of material performance testing, and relates to a multiaxial salt spray corrosion fatigue crack propagation testing system. Background technique [0002] With the continuous development of society and economy, land resources are increasingly tense, people have gradually turned their development goals to the ocean with rich resources, and in recent years, the development trend has been accelerated, and various marine engineering equipment has been continuously introduced. Since many marine equipment (such as oil and gas resource extraction, processing, storage and transportation equipment, etc.) contain flammable, explosive, and toxic substances, once they fail, catastrophic accidents such as fire, poisoning, and environmental pollution often occur. In order to improve reliability, more More and more offshore engineering equipment adopts the damage tolerance design method based on the principles of fracture m...

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Problems solved by technology

[0003] Although the existing Chinese patent documents "a fatigue crack growth rate test environment device under a corrosive environment" (authorization number: CN101358929A), "a fatigue test test system under a corrosive environment" (public number: CN103439202A), "spring Salt spray fatigue test device" (public number: CN102944511A), "a salt spray environment device for fatigue performance test" (notice number: CN201589746U), "high temperature salt spray test device" (notice number: CN202994631U), etc. have been published Some corrosion fatigue performance tests and salt spray environment simulation devices have been carried out, but they still cannot meet the actual needs of testing the fatigue crack growth rate under the joint action of multiaxial load and salt spray environment

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