Device for testing fatigue crack growth rate of metal material in aqueous corrosive medium

Abstract

The invention aims to provide a device for testing a fatigue crack growth rate of a metal material in an aqueous corrosive medium. The device comprises a liquid storage container, a test container and a fatigue testing machine, wherein the liquid storage container is filled with a corrosive solution for testing, the corrosive solution sequentially flows through a rust filtering device and a temperature controller through a water supply hose to be communicated with the test container, an upper pressure head and a lower pressure head are mounted on the fatigue testing machine respectively, a test piece is clamped between the upper pressure head and the lower pressure head and placed in the test container, the upper pressure head has two loading points matched with the upper surface of the test piece, the lower pressure head has one loading point matched with the lower surface of the test piece, an extensometer is mounted in a crack opening of the test piece and connected with the fatigue testing machine, an overflow pipe is arranged in the test container and communicated with the corrosive solution in the liquid storage container through the water returning hose. The device can completely protect the extensometer and the fatigue testing machine from being corroded by the corrosive solution, the labor intensity can be reduced, and the testing accuracy of a fatigue crack length can be improved.

Description

technical field [0001] The invention relates to a test device, in particular to a metal fatigue crack growth rate test device. Background technique [0002] Fatigue problems of metal materials in aqueous corrosive media are ubiquitous in the fields of ship and ocean engineering, petrochemical, aviation and nuclear power. In order to carry out reasonable material selection and evaluation, fatigue crack growth rate testing of metallic materials in aqueous corrosive media is required. [0003] The difficulty of the fatigue crack growth test in the aqueous corrosive medium environment lies in the installation of the extensometer and the design of the corrosive solution circulation device. GB / T6398-2000 recommends using compact tensile (CT) specimens and central crack tensile (MT) specimens for testing. The installation position of the extensometer of the CT specimen is at the same level as the crack growth plane, and only the horizontal fatigue testing machine can be used for ...

AI Technical Summary

Problems solved by technology

However, when there is a corrosive medium, it is generally difficult to accurately observe the crack length with a reading microscope due to the influence of the corrosive solution.

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