TEST METHOD OF THIN-WALL SPECIMENS UNDER STRESS Russian patent published in 2012 - IPC G01N17/00 

FIELD: machine building.

SUBSTANCE: test method of thin-wall specimens under stress involves operations of action with load, medium and field on the tested material specimen. Also, the method involves measurement of the required parameters and make-up of the conclusion on the degree of change of the specimen's characteristics. At that, at the first test stage the bending load on the specimen is created by forming preliminary deflection and by further tightening of two opposite edges of the specimen of rectangular shape to each other by means of a rod. Then, tension of convex side of the specimen and compression of concave side of the specimen is performed. After that, initial geometrical parameters of deformed specimen are measured. Then, corrosion-resistant protective coating is applied to one of the specimen's surfaces if necessary. The specimen is kept in corrosive medium and in the specified field during certain period of time; then, it is withdrawn from working medium and field; applied load is relieved from the specimen and geometrical parameters of the specimen are measured again. At the second stage of the method a fragment of circular shape in plan view is cut from the specimen, fixed on the measuring device for creation of one-sided pressure on the surface of the involved fragment. Then, height of the formed dome is measured as the pressure increases and mechanical characteristics of the involved fragment are determined. At that, relative corrosion degree is calculated at equal pressures by formula where λ - relative corrosion degree, H_p - height of the specimen's dome with strained surface at corrosion; H_c - height of the specimen's dome with compressed surface at corrosion.

EFFECT: simplifying the specimen's preparation, test technique and procedure; providing the load uniformity during corrosive test; enlarging the possibility of maintaining the loaded specimens in various media and fields.

5 cl, 2 dwg, 9 tbl