SU840156A1 - Method of strengthening torsional shafts - Google Patents

Description

(54) METHOD OF STRENGTHENING THE TORSION SHAFT

The invention relates to methods of strengthening treatment of torsion shafts and can be used to strengthen any parts of cylindrical shape machines, operating arikrutilnyh pulsing loads, such as shafts of heavy transport machines (tractors, automobiles, etc.). In modern machine building, for the manufacture of torsion shafts of heavy transport machines operating under high pulsating loads, steel 45KHNMFA is usually used. low temperature aging p. . There is also known a method of processing products, according to which the products are subjected to a TMT, the surface work-hardening and finishing operation of which is cold deformation by twisting 2D. Closest to the proposed method is a method that includes thermomechanical treatment with torsional deformation and with subsequent cold work-hardening operations in combination with low-temperature aging, which are carried out many times with L3J. The existing method of hardening provides high performance characteristics of full-sized torsion shafts. However, it has the complexity of performing strengthening operations. Cold work hardening of such products is carried out by zevlevolivan. For this purpose, bulky and powerful installations are used for multiple twisting at a certain angle of the shaft in a quenched condition with a martensitic structure. After each cold work hardening cycle, a two-hour low-temperature tempering was performed. The purpose of the invention is to simplify the propaos with the preservation of the strength characteristics in the field

Delivered: del found by the fact that according to the method of strengthening products, including thermomechanical treatment with torsional deformation, no temper- ature tempering, instead of subsequent cold work-hardening operations in combination with low-temperature aging, the hot-working wire is covered with a surface and a surface, high frequency to quenching temperatures and quenching in a continuous-sequential manner.

Example, Thermal mechanical processing of natural torsion wapes made of 45 KhNMFA steel in the amount of 75 pcs. The diameter of the working part is 5 mm and the shaft length is 130 mm.

The shafts heated to 88 ° C / are subjected to thermomechanical treatment with deformation torsion and subsequent two-hour tempering of 111e and 180-2OO C. After that, the shafts are subjected to surface heating by high-frequency currents to a temperature of about 88 ° C and quenching in a continuous-sequential manner.

Treated in this way, in-situ shafts are subjected to bench tests under pulsating torsional load. As shown by testing, the strength characteristics are at about the same level as after processing by the well-known method. This is achieved by creating a second genus of compressive residual stresses on the surface of the products.

I The proposed technology of torsion shafts can significantly reduce the labor intensity of processing, increase labor productivity and reduce the cost of processing products. Thus, processing by a known method provides a fatigue limit of 2 kg / mm, and a proportionality limit of nu lOSKF / Mivf. Processing of products from the same steel 45ХНМФА on the proposed method allows to obtain the fatigue limit

Cuj 141 kg / mm

 189 kg / mm

PC

Claims (3)

1. USSR author's certificate number 464631, cl. C 21D 7/14 ,, 1974. 2. USSR author's certificate number 406916. class. C 21D 7/14, 1971. 3. USSR author's certificate No. 513091, cl. C 21D 7/14, 1974.