SU1302174A1 - Method of nondestructive checking of part quality - Google Patents

Abstract

This invention relates to a testing technique. In order to improve quality control by taking into account the elastic-plastic deformations of the parts, the reference part is statically loaded first. When loading, a stress – strain – stress pattern in the most loaded section is recorded. After unloading the reference part, its residual deformation C and the work A g of elastoplastic deformation are measured. Parts subjected to non-destructive quality control are loaded according to the same scheme as the reference part, with a load that ensures the cost of the same work of elastoplastic deformation as that of work A. After unloading the part, its residual deformation is measured - and the quality of each part is judged by comparison. with residual deformation of the reference part. (/) about 4

Description

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The invention relates to the study of the strength properties of materials and can be used for non-destructive quality control of parts.

The purpose of the invention is to improve the accuracy of quality control of parts by taking into account the elastoplastic deformations of parts.

The method is carried out as follows.

For parts that will be subjected to nondestructive quality control, a reference part is used,

The reference part is subjected to static loading beyond the elastic limit with registration of the stress-strain diagram in the most loaded section. Then, the reference part is unloaded and its residual deformation is measured. The load value and the loading pattern of the reference part are chosen from the conditions of operational loading, and the residual deformation of the reference part should not exceed the permissible value.

The loading diagram of the reference part is processed and the work is determined

And 3 of its elastoplastic deformation.

The remaining parts subjected to non-destructive quality control are loaded in the same way as the reference part with a load that ensures the cost of the same work of elastoplastic deformation as work A, the same cross section as the reference part. After unloading the part, its residual strain S. is measured and the quality of each part is judged by comparing with the residual strain of the reference part.

Primer p. Experienced nadressornye beams trucks freight cars

Compiled by M. Kuzmin Editor O. Yurkovetskaya Tehred M. Khodanych Proofreader S. Shekmar

1211/43

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VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Production and printing company, Uzhgorod, st. Project, 4

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models 18-100, Beam material steel 20 G1FL. To register the stress-strain diagrams, strain gauges with a base of 20 mm, ohmic resistance of 200 ohms and a plotter were used.

The work of the elastoplastic deformation of the material in a dangerous section of the reference beam under loading according to the three-point bend scheme is 150 J. The rest of the beams were loaded on condition that the same work was expended on the elastic-plastic deformation.

Residual deflection of beams 0.38-0.144 mm. After static tests, the beams were loaded with a cyclic load until destruction. Cyclic tests showed that the fatigue strength correlates with the assessment of the quality of the beams by the residual deflection at a given amount of work of elastoplastic deformation.

Claims (1)

Invention Formula The method of non-destructive quality control of parts, by which the reference part is subjected to static loading beyond the elastic limit, the reference part is unloaded and its residual deformation is measured, all other parts are similarly loaded, and their quality is compared by comparing residual deformation with that, in order to improve the accuracy of quality control by taking into account the elastoplastic deformation of parts, when a reference part is loaded, the work of its elastoplastic is measured deformation, and the load on the remaining parts are chosen from the condition of the cost of the specified work of deformation.