SU1698041A1 - Method for ultrasonically hardening cylindrical workpiece surfaces - Google Patents

Abstract

The invention relates to the processing of metals by pressure, in particular to ultrasonic hardening and finishing. The purpose of the invention is to increase the productivity and quality of machining parts. The part is rotated and subjected to surface plastic deformation with static force by self-rotating roller tools, successively located one behind the other at an angle of a and 180 °. - and to the axis of the part. For this, axial and radial movements of the rollers are limited, and ultrasonic vibrations from the concentrator are transmitted to the rollers at a certain distance b. Angle a 72.5 ... 77.5 °. As a result, it is possible to obtain hardened surface layers with a lower surface roughness with high process efficiency. 1 hp f-ly, 2 ml. 1 tab.

Description

The invention relates to the processing of materials by pressure, in particular to the ultrasonic hardening and finishing treatment of metal parts.

The purpose of the inventions is to increase productivity by intensifying the process and the quality of the treated surface by reducing the roughness of the treated surface.

On fmg. 1 shows a scheme for carrying out a method for treating the outer cylindrical surfaces of parts with an ultrasonic instrument; in fig. 2 shows section A-A in FIG. one,

The cylindrical part 1 rotates at a speed p in contact with rotating cylindrical rollers 2 and 3, which are affected by a static force Py, ultrasonic vibrations through the concentrator 4 from the magnetostrictive transducer 5. as well as by Rc force, to avoid axial movement through the stop 6.

During processing, rollers 2 and 3, concentrator 4 in place with magnetostrictive transducer 5 and support 6 move along part 1 with feed S. One of the rollers is inclined at an angle to the axis of the slide 1, from the other at an angle of 180 ° and As a result, they rotate around their axes in different directions. Ultrasonic vibrations to the rollers from the concentrator are transmitted in two zones that are separated from the concentrator axis at a distance b / 2. This is achieved by making a slot in the end of the concentrator parallel to the workpiece axis of width b.

The static clamping of the rollers to the part is carried out by a mechanical spring (not shown), which acts on the system

Os

Yu

00

eight

magnetostrictive transducer - rollers and.

The stop b is rigidly fixed to the converter case 5 (not shown). When machining the rollers, when in contact with the rotating part, axial displacement forces are experienced, therefore the rigid support is responsively developing the resulting force PC.

The derivation of the formula — for calculating the slot width at the end of the concentrator — was calculated so that traces of the end of the concentrator on the rollers do not fall off after the impact of the surface of the part on the surface of the roller. The dimensions of the major axis of the contact point of two cylindrical surfaces with no parallel axes are determined by the formula

G1 P

Here r, where n is the radius of curvature

surface to be treated; n is the radius of curvature of the rollers.

l-1-i,

B-Ei + E2

where / i, fi2 are the Poisson ratios of parts and rollers;

Ё1, Е2 - elastic moduli of part materials and rollers;

N is a normal load, in this case Py. .

Example. Ultrasonic treatment of the outer cylindrical surfaces with a diameter of 88 mm of parts made of steel 45 is carried out. The initial surface roughness is Ra 0.63; hardness ldc 48-54. Standard rollers with a diameter of 5 mm and a height of 1 b mm made of hard alloy VKb are used, whose working surface is polished. up to a roughness of Rz 0.08.

Ultrasonic vibrations are transmitted to the rollers from the PMS-15A-18 magnetostrictive transducer through a conical concentrator, the working end of which has a diameter of 20 mm with a slot installed parallel to the axis of the workpiece.

The magnetostrictive transducer is installed in a special device, which is fixed in the tool holder of a lathe. The converter is clamped by a spring that is calibrated in kgf.

A special device is fastened to the device with a stop which is smoothly applied to the converging ends of the rollers and is rigidly fixed in this position.

The magnetostrictive transducer is powered by an UZG2-4M ultrasonic generator.

The roughness parameters of the treated surfaces were measured on a Model 201 profilometer-profilograph, and the hardness and depth of the hardened layer were measured on a PMT-3 microhardness meter.

The hardening process is carried out on

0 base lathe, which adapt all the necessary devices.

Baseline data, geometric and mechanical characteristics of the hardened surfaces are given in the table.

5 The hardening results are compared with the results obtained when implementing the method according to the prototype, in which a forcibly rotating and longitudinally moving roller of hard alloy QB with a diameter of 5 mm is used. In addition, the table shows the results of the implementation of the method according to the prototype during a long pass along the workpiece. The coefficients q 1, fi2 and the values of Ei and

5 Е2 for calculating the width of the slot in the butt is taken from the book Tselikov A.I., Nikitin G.S., Rokot and S.E. Theory of longitudinal rolling. M .: Metallurgi, 1980, p. 32.

As can be seen from the above results,

0 the choice of the angle of inclination of the rollers to the part axis less than 72.5 ° (70 °) leads to a certain decrease in the depth and hardness of the hardened layer at the lowest surface roughness. However, the main

5 the inability to reduce the angle of inclination is the need to increase the diameter of the working end of the concentrator and the length of the rollers, which leads to a decrease in the amplitude of the ultrasonic inspection, which causes a decrease in the depth of the reinforced layer and its hardness, as well as a decrease in the durability of the rollers as a result of their breakage increase the distance between the zones of the UZK application.

5 An increase in the angle of inclination of the rollers above 77.5 ° (80 °) leads to an increase in the roughness of the treated surface due to the difficulty of the free rotation of the rollers and, as a result, they often slip, and this leads to a deterioration of the roughness of the treated surface.

An increase in the slot width above 17a & (4.1 mm) leads to a certain decrease in the depth of the hardened layer and its hardness, which is caused by a decrease in the overall intensity of the ultrasonic inspection in the treatment area, and the decrease in the durability of the roller due to an increase in the area between the zones of the ultrasonic inspection, development significant bending vibrations in the roller and its breakage.

A reduction in the slot width less than 11 ae (1.8 mm) leads to an increase in the roughness of the treated surface and a decrease in the durability of the rollers due to the impact zone of the ultrasonic scanner on the rollers in the zone of impact of the ultrasonic scanner on the part, which leads to scuffing on both parts and on the rollers .

The use of the proposed method provides an increase in the quality of processing, an increase in the productivity of processing, a decrease in the roughness of the treated surface and an expansion of the technological capabilities of the process.

Formula 1 and 1. The method of ultrasonic hardening of the outer cylindrical surfaces of the parts, in which the part is rotated, surface plastic deformation is carried out with a static force by a cylindrical roller set at an angle of "mowing the part and moving along the axis of the part, forming which is located parallel to the forming part, and the ultrasonic vibrations are performed by the end of the concentrator at the spot of contact of the roller with the part, characterized in that, in order to increase the production

due to the intensification of the process and quality by reducing the roughness of the treated surface, surface plastic deformation is carried out with an additional roller mounted on the concentrator at an angle of 180 ° —and to the part axis, both rollers installed with the possibility of forced rotation and axial and radial directions, and a slot is made diametrically along the end of the concentrator, the width of which is chosen from the ratio

gu ge r ha

H "1 E,

m

M; mm

where n is the radius of curvature of the workpiece, mm;

ry is the radius of curvature of the rollers, mm;

i 1 2 - Poisson's ratio of part materials and rollers;

EI and E2 — elastic moduli of roller materials and parts, Pa;

N - normal load, kgf;

ft is the coefficient depending on the p / r2 ratio; equal to 1..5.

2. The method according to p. 1, characterized in that the angle is in the range of 72.5 ... 77.5 °.

Montur / Gürz.

MSr # / Yar0M

3

FIG A

p ° lA

Claims (2)

Claim 1. The method of ultrasonic hardening of the outer cylindrical surfaces of parts, in which the part is rotated, 20 surface plastic deformation is carried out with a static force by a cylindrical roller mounted at an angle a to the axis of the part and moving along the axis of the part, the generatrix of which 25 is parallel to the forming part, and ultrasonic vibrations carry out the end face of the concentrator at the spot of contact of the roller with the part, characterized in that, in order to increase productivity due to intensification process and quality by reducing the roughness of the treated surface, surface plastic deformation is carried out by an additional roller mounted on the hub at an angle of 180 ° to the axis of the part, both rollers being installed with the possibility of forced rotation and restricting their movement in axial and radial directions, and diametrically, a slot is made at the end of the concentrator, the width of which is selected from the relation where and is the radius of curvature of the workpiece, mm; G2 - radius of curvature of the rollers, mm; μ 1 and μ 2 ^_ Poisson's ratios of the materials of the part and rollers; Ει and Eg are the elastic moduli of the roller materials and parts, Pa; N - normal load, kgf; β is a coefficient depending on the ratio p / g; equal to 1..5. 2. The method of pop. 1, characterized in that the angle is chosen within 72.5 ... 77.5 °. Way The angle of the axis of the rollers to the axis of the part, deg Zorina slots at the end of the hub, mm Indenter clamping force, mm Amplitude of ultrasonic testing of the indenter, microns Part rotation speed, rpm Indenter feed along the part axis, mn / rev Surface roughness after processing, μm The depth of the hardened layer, mm The hardness of the material in the hardened layer, kgf / mm * Resistance of roller indenters, pcs. 1 70 2.9 70 fifteen 130 0.23 0.05 0.15 6lu 84 2 72.5 2.9 70 fifteen 130 0.23 0,07 0.19 δ1b 45 3 - 75 2.9 70 fifteen 130 0.23 0.09 0.22 625 130 77.5 2.9 70 fifteen 130 0.23 0.7 0.26 635 128 5 80 2.9 70 fifteen 130 0.23 0.25 0.28 640 125 6 75 1.8 70 fifteen 130 0.23 0.21 0.21 820 89 7 75 2,3 70 fifteen 130 0.23 0.09 0.22 625 125 8 75 2.9 70. fifteen 130 0.23 0.09 0.2 62 ‘ 135 9 J 75 3,5 70 fifteen 130 0.23 0.1 0.21 130 10 75 *,1 70 • fifteen > 30 0.23 0.09 0.20 616 65 Prototype ^ 75 40 fifteen 130 0.23 One pass 0.33 0.20 625 96 75 40- fifteen 1zo 0.23 Passageway 0.22 0.23 630 105