Stress corrosion test method and device for metal sheet pre-cracked sample

Abstract

The invention discloses a stress corrosion test method and a stress corrosion test device for a metal sheet pre-cracked sample. The method comprises the following steps of: fixing one end of the sample on a bearing wall, clamping the other end of the sample by using an upper clamping plate and a lower clamping plate and fixing; clamping a test section of the sample by using a corrosion environment test box; pre-estimating the initially applied stress field intensity factor according to the threshold stress field intensity factor of crack propagation of similar metal materials, wherein the pre-estimated value is greater than the threshold stress field intensity factor of the crack propagation of the metal materials; loading stress to the metal sheet sample, measuring the crack length of the sheet sample to obtain a crack stress field intensity factor, and stopping loading the stress when the crack stress field intensity factor is equal to the pre-estimated value; filling a corrosion medium in the corrosion environment test box; measuring the length of a crack at the tip of the pre-cracked sample at intervals of certain time; and measuring the crack length and the loaded stress after the crack stress field intensity factor is stabilized to obtain the threshold stress field intensity factor of stress corrosion crack propagation. The method is convenient to operate and high in measuring accuracy.

Description

technical field [0001] The invention relates to a device and a test method for stress corrosion testing of metal thin plate pre-cracked samples, belonging to the technical field of electrochemical measurement in atmospheric erosion, corrosion or anticorrosion measurement. Background technique [0002] In the use environment, mechanical systems and components are usually subjected to certain stress, so stress corrosion damage is more common in corrosion damage, and the corrosion resistance (corrosion stability) of materials is one of the important parameters that determine the working life of systems and components. one. Through the stress corrosion test, a preliminary study of stress corrosion can be carried out: determine the mechanism, how to select suitable materials, further develop new alloys resistant to stress corrosion, and discuss the protection methods of materials against stress corrosion. The stress corrosion test of metal pre-cracked specimens is one of the imp...

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Problems solved by technology

But there are still deficiencies in it. The crack tip of the pre-cracked sample must meet the plane strain state, so it stipulates that the pre-cracked sample must have a relatively large thickness, and the thin plate sample is widely used in practice, but according to the existing The stress corrosion test method of the WOL type sample, that is, the pre-cracked sample that satisfies the plane strain state, lacks pertinence in the stress corrosion test of the pre-cracked sample on the thin plate, which will lead to the test results being too conservative and safe, and lacking engineering application value

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