METHOD OF AUTOMATIC DIAGNOSTICS AND CONTROL OF THERMAL POWER PROCESSING OF LOW STIFF AXISYMMETRICAL PARTS, AND DEVICE FOR ITS IMPLEMENTATION Russian patent published in 2012 - IPC C21D11/00 

FIELD: metallurgy.

SUBSTANCE: automatic diagnostics and control method used for thermal power processing of low stiff axisymmetrical parts involves installation of the tested workpiece specimen into the rig mounted into electric furnace, one end of which is rigidly fixed relative to the rig and the other end is rigidly fixed in clamping mechanism of power loading, and at the same time, temperature power factors are applied to it in axial direction. Furnace temperature is equalised throughout its length and axial tension force is applied; at the same time, current size of workpiece specimen diameter, as well as temperature power mode is controlled; values of transverse deformations, i.e. thinning places are equalised throughout the length and mode of the furnace cooldown is switched on. Device used for the implementation of the above method of automatic diagnostics and control of thermal power processing of low stiff axisymmetrical parts includes a rig with fasteners of workpieces and a heating element. Workpiece witness and workpiece specimen are installed in the rig with support cover plates and with two openings for grips of workpieces with spherical nuts; ends of grips are fixed in openings of grips with inner thread, and heat insulating gaskets are installed between ends of grips and specimens and between cover plates of the rig and heating chamber. Device also includes diameter thinning control sensors that consist of feelers made from material with minimum linear expansion coefficient in the form of compression spring, primary converters of linear movements and amplifiers; besides, thermal power processing device is equipped with automatic control system that includes temperature sensors mounted into the workpiece witness body; linear movements - thinning places of diameters and length of workpiece witness of long assembly installed on foundation and included in control circuit. Control system contains three control loops, one of which is provided with possibility of controlling the value and rate of longitudinal deformation, the second one is provided with possibility of thermal effect, and the third one - with values of thinning places and uniform plastic deformation, besides, each control loop includes sensor, amplifier, analogue-to-digital converter, control unit and drive.

EFFECT: increasing stability of sizes and shape of long low stiff parts by eliminating the directivity and minimising the level of axial residual stresses and formation of their uniformity throughout the workpiece length.

2 cl, 2 dwg