Additive product residual stress testing method

Abstract

The invention discloses a method for testing residual stress of an additive product. The method is characterized in that firstly by electrolytic polishing, a rough surface of the additive product is performed, then, corrosion current and time parameters of electrolysis are controlled, layer-by-layer deep stripping of the product is realized, then, in the layer-by-layer deep stripping process, peeling is performed, the residual stress along the stripping depth direction is measured through an X-ray diffraction method. The method is advantaged in that problems that a surface of the additive product is rough and cannot be directly measured are solved, the limitation that only the surface can be measured by a pure X-ray measurement technology is overcome, measurement of the residual stress ofthe additive product in the depth direction is realized, and the test method is simple to operate and controllable in depth.

Description

technical field [0001] The invention relates to the technical field of residual stress testing methods, in particular to a residual stress testing method for additive products. Background technique [0002] Non-uniform elastic deformation or non-uniform elasto-plastic deformation in the material will generate residual stress, which is a reflection of the elastic anisotropy and plastic anisotropy of the material. Single-crystal materials are anisotropic. Although multi-phase polycrystalline materials are isotropic macroscopically, in the micro-region, due to the existence of grain boundaries and different orientations of grains, the elastic-plastic deformation is uneven. In practical engineering applications, the main reasons for uneven deformation of materials are: (1) uneven elastic-plastic deformation along the cross-section during cold and hot deformation; (2) uneven internal temperature distribution during heating or cooling, resulting in thermal expansion and contractio...

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Problems solved by technology

[0004] The applicant found that the measurement reliability of the ultrasonic method among the above measurement methods has not reached the level of widespread application; the magnetic method is only applicable to ferromagnetic materials, and has certain limitations; the blind hole method causes secondary damage to the product and produces new Residual stress; neutron diffraction method is difficult to popularize and apply in industrialization due to expensive equipment; X-ray diffraction method is the most widely used test method, but due to the limited penetration depth of X-rays, it can only be limited to the measurement of surface residual stress and cannot realize product The measurement of internal residual stress, while the surface roughness of the additive product also limits the direct application of the above method

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