SU744043A1 - Method of metal strengthening - Google Patents

Description

(54) METHOD OF STRENGTHENING METALS

The invention relates to the field of metal hardening by surface plastic deformation. The known method of metal hardening is that the surface metal layer is deformed by a tool moving relative to it, the deframs of which the surface is characterized by the initial configuration of the deformation front 1. However, the known method does not make it possible to achieve a significant degree of reinforcement with relatively small deformation forces. This significantly narrows the field of application of this method, for example, during the strengthening and finishing treatment of curved steels. In order to implement this method, it is necessary to create special devices for an induced change, a number of technological parameters of the process (working pressure and tool feed), which increases the economic costs. In addition, the known method has limited performance. The purpose of the invention is to reduce costs, improve processing quality and increase productivity. The goal is achieved by the fact that in the process of deforming the surface layer of the metal, the conformation of the deformation front in the machining direction is changed, ensuring that the areas with the maximum strength and the concave curve of the deformation front with the maximum curvature match the areas with the minimum degree of strengthening, and the curve with the minimum degree is strengthened deformation front also with maximum curvature. The method is carried out as follows. On the hardened surface, zones with different degrees of hardening are identified. The dependence of the required degree of hardening on the configuration of the deforming surface of the tool, which ensures its achievement, and the program for changing the configuration of the deformation fraet on the displacement of the tool are compiled and set into the appropriate device. Assign the technological parameters of hardening,

which remain unchanged during processing. In the course of strengthening treatment, the geometry is deformed according to the Esan program by deforming the tool surface in the machining direction.

FIG. 1 shows the deformation front during hardening by surface plastic deformation according to the proposed method; in fig. 2 is a section A-A in FIG. 3; in fig. 3 is a section bB in FIG. 2

According to the proposed method of controlling hardening, a change is made in the configuration of the deformation front in the direction of movement of the tool S. For example, if a concave front is created (see position A in Fig. 1), the deformable metal wave propagates and concentrates in a local area in front of the tool. At the same time, plastic flows of metal of different directions collide, and the deformed metal in this area is under conditions of multilateral compression, which is. leads to an increase in the intensity and degree of deformation hardening of the metal in this area. As the curvature of the strain front increases, the degree of strain hardening of the Aupr metal to dynp increases. . in the case of creating a convex deformation front (see position B in Fig. 1), with increasing curvature, the conditions for the extension of the extremes are more and more eased; layers of meteshla on the deformation front. As a result, the stress of the strain field and in the layers is weakened and, thus, the entire area of the metal adjacent to the tool receives a reduced strain hardening & vti (j ..

A device implementing the proposed method consists of a chassis 1, in which a shaft is mounted on shaft 2

The table shows the test results.

In order to achieve the same "degree of hardening in a known manner, it is necessary to create in the area of the zone Ara" an occuring of at least P

disc cam 3, the profile of which has a variable configuration with zgshannoy-curvature. The deformation elements 6 (rollers, balls) in contact with the base plate 7, designed to transfer the working pressure to the workpiece surface 8 with the required force k, are pressed against the profile surface of the cam 3 by the springs 4.

For hardening, flat samples of 20x100x300 mm in size from hot-rolled steel 10 GOST 1030-60 with initial roughness of class 5 and initial hardness of 110-120 NW are used. The length of the sample is required to obtain

5 two zones with varying degrees of reinforcement. Zone A 120 mm long with a hardness of at least 210 HB, zone B 180 mm long with a hardness of at least 150 HB.

0

To achieve this goal: in the process of moving the device in the direction of end S (see Fig. 3), when the cam 3 rotates according to a given program at the required speed. - the spring-loaded deforming elements 6 reproduce the cam 3 profile and, accordingly, rotate it, change the front configuration deformation in the direction of movement of the device in such a way that in the area of zone A, a front is created with a convex configuration, deformations with, the curvature radius Riq, el5 mm, and in the area of area B a concave deformation front configuration is created with curvature curvature

5 RKP ° 10 mm. The remaining hardening parameters remain constant: maximum pressure P 800 mN / m% feed S 0.06 mN / rev, speed V 60 m / min, cooling - machine

0 oil. The hardening effect is estimated by the increment, hardness of DNDV, which is measured along the longitudinal center line of the specimens at three points of each reinforcement zone.

1200 mN / m, and in the area of zone B not less than R 1000 mN / m.

Claims (1)

Thus, a given degree of hardening according to the proposed method is achieved with forces 20-25-25% less than in a known manner. This allows highly efficient control over the degree and distribution of simplifications over the treated surface without changing other technological parameters (speed, strain). This, in turn, expands the technological capabilities of the method and allows high quality and productivity. To harden thin-walled and low-stiff parts, as well as to ensure high efficiency of the process during hardening and finishing of hardened steels. The application of the proposed method allows to increase the degree of hardening and the quality of the surface layer, to increase the productivity of the process and reduce the economic costs. The invention of the method of hardening metals, which consists in the fact that the surface ASR / III a phi &.; { Aa ( ± " Fi.2.2 The metal layer is deformed by a tool moving relative to it, the deforming surface of which is characterized by the initial configuration of the deformation front, characterized in that, c. in order to reduce economic costs, improve processing quality and increase productivity, in the process of deforming the surface metal layer, the configuration of the deformation front in the processing direction is changed, ensuring that areas with the maximum hardening of the concave deformation front curve are maximized to the maximum curvature and the sections with the minimum hardening degree are convex the curve of the deformation front is also with a maximum curvature. Sources of information taken into account in the examination 1. USSR author's certificate 375169, cl. 24/39/00, 1973. can: fi bb Fa8.