SU1087809A1 - Method of investigating pipe material mechanical properties - Google Patents

Description

The invention relates to studies of the * mechanical properties of materials and structural elements, and in particular to methods for studying the mechanical properties of pipe material. ₅

A known method of studying the strength of a pipe, which consists in the fact that the pipe is loaded with internal pressure until it breaks, the fracture pressure is recorded, and it is used to judge the strength of the pipe material C I3.

The disadvantage of this method is the impossibility of determining the elastoplastic properties of the pipe material, since the loading by internal pressure allows only the carrying capacity of the pipe to be estimated.

The closest to the invention in terms of technical nature and the achieved result is a method for studying the mechanical properties of pipe material, which consists in cutting the pipe into samples, stretching them and judging the tensile test results on the mechanical properties _of $ ₂ material C 2 3.

In the known method, the pipe is cut in parallel planes, while the samples are obtained in various shapes. _thirty

The aim of the invention is to improve the accuracy of research by manufacturing the same samples.

This goal is achieved by the fact that according to the method of research 35 of the mechanical properties of the material of the pipe, which consists in the fact that the pipe is cut into samples, stretched them and according to the results of tensile tests judge the mechanical properties of the material ⁴⁰ , before cutting the pipe is pumped along the outer and inner surfaces to the formation of a thinned working section in its middle part and thickened gripping sections 45 at the ends of the pipe, and the cuts are made along planes passing through the axis of the pipe.

The manufacture of identical samples allows the study of material properties in different sections of the pipe under the same test conditions.

In FIG. 1 shows the central section of the pipe after its groove; in FIG. 2 - cross section of the working section of the pipe after grooving.

The method is as follows.

The pipe 1, the material of which is studied, after the manufacture of the pipe or its operation, is pumped along the outer and inner surfaces to form a thinned working section 2 in its middle part and thickened gripping sections 3 and 4 at the ends of the pipe.

When grooving on the outer surface of diameter D and when grooving on the inner surface of diameter d, the fillets perform the same radius R.

After grooving, the pipe is cut into samples 5 (Fig. 2) along the planes 6 passing through the axis of the pipe. Samples 5 having a cross-sectional shape of an annular sector are subjected to additional mechanical processing before loading to obtain the same thickness over the cross section of the sample, i.e. acquire a flat shape.

Then, the samples are installed by gripping sections 3 and 4 in a loading device (not shown), they are stretched, and the mechanical properties of the material are judged by tensile tests. ι

The invention improves the accuracy of the study of the mechanical properties of the pipe after its manufacture or after operation and to obtain a sufficient amount of information about the properties of the material in different sections of the pipe.

VNIIIPI Order 2645/36

Circulation 823 Subscription

Branch of PPP Patent,

Uzhhorod, st. Project, 4

Claims (1)

METHOD FOR STUDYING THE MECHANICAL PROPERTIES OF PIPE MATERIAL, which consists in cutting the pipe into samples, stretching them and judging by tensile tests the mechanical properties of the material, characterized in that, in order to show the accuracy of the study by making identical samples, they pierce the pipe before cutting on the outside and inside; prior to the formation of a thinned working area in its middle part and thickened gripping areas at the ends of the pipe, and the cuts are carried out along the planes passing through the axis of the pipe. Fi11