SU850684A1 - Method of making tool from high-speed steel - Google Patents

Description

(54) METHOD OF MANUFACTURING A TOOL FROM QUICKLY CUTTING STEEL

I

The invention relates to the processing of metals and can be used in the tool industry.

A known method of making an instrument involves heating to a quenching temperature, hot plastic deformation, quenching and tempering. 1 J.

Such treatment provides the required structure, hardness and red hardness at certain rates of deformation and intensive cooling.

In addition, with this method of making a tool, the surface is oxidized and gassed (HI, Au).

Closest to the present invention is a method of making a drill, including heating the workpiece to the rolling temperature, rolling, straightening at 900 ° C, air cooling, grinding, hardening with a salt bath, and straightening f2.

However, the method requires reheating to the quenching temperature and also causes a decrease in quality due to oxidation and saturation of the surface with gases.

The purpose of the invention is to improve the quality of the tool.

To achieve this goal, in a method that includes heating to rolling temperature, rolling, heating, quenching, cooling: kdenia and straightening, heating for quenching and cooling to 950-1050 s is carried out in vacuum, cooling to 250-400 s is produced by inert gas, and the subsequent cooling is carried out in air in a fixed state.

Claims (2)

Vacuum cooling to l050-95Cf C of heated billets is necessary to reduce surface stresses, since the linear expansion coefficients of the matrix and high-speed steel caroids at high temperatures have a significant difference. THAT creates strain anisotropy in different directions, especially with accelerated cooling. The rapid cooling of the blanks with an inert gas from the quenching temperature prevents the release of caroids from austenite, which can be located along the grain boundaries, impairing the strength of quenched blanks. Cooling of blanks in an inertial gas environment is carried out up to 250-400 ° C in order to cool the chamber from unloading; A method of making drills is as follows. The billet is heated to rolling temperatures of 1000-1100 ° C in an inductor and fed into a rolling stand, where it is rolled to form ribbons and backs. In the process of rolling, the billet's temperature drops to 900 ° C. The rolled billet enters a vacuum electric furnace, where it is heated to the quenching temperature. In the process of heating the drill billet to the quenching temperature and holding at a given temperature, the billets are degassed. Then, the blanks enter the chamber where they are cooled, first cooled in a vacuum, and then with an inert gas to 230CZZ. Heating and cooling of billets in vacuum is EXACTED at 2.5-1 10 mm Hg with leakage of not more than 20 lkmm / s. Further cooling of the blanks is carried out outside the cooling chamber in the correct device in the clamped state to room temperature. Example. A 4–4 mm spiral drill bit of steel R6M5 is heated in an HDTV inductor to a rolling temperature of 1000–1100 ° C. After this, the preparation enters the rolling stand of the longitudinal helical rolling mill, where the profile of the drill is formed. In the process of rolling, the billet is cooled to 900 C. With such a temperature, it enters the vacuum furnace charging chamber along the chute | and then into the heating chamber. There it is heated to a hardening temperature of 1200-1220 C and held 44 for 3-4 minutes. At this temperature, the billet enters the discharge chamber of the electric furnace and there is cooled first in vacuum to. An inert gas is then introduced into the chamber, in which the billet is cooled to 250-400 ° C. Then the billet is fed to the correct device, in which it is further cooled to room temperature in the clamped state. The proposed method can be carried out on rolling mills operating in industry, equipped with a vacuum heating device and a right-hand calibration unit consisting of three rotating rolls. The application of the method simplifies the production process of drills, increases productivity and reduces labor intensity, since it eliminates a number of independent operations, calibration of the workpiece by grinding on the outer diameter, annealing before hardening, polishing the grooves. The quenching operation is combined with rolling / in connection with which the number of heatings of the workpiece is reduced, and inter-operation and interdepartmental transportation of the workpieces is also excluded. The proposed method improves the quality of harvested products. Rolling in rolls with crimping to a bar temperature from a given size of 250 ° C to 50 ° C ensures the calibration of the outer diameter of the blanks and their straightness, as well as the concentricity of the profile with respect to the axis. Reducing the residence time of the ingots in the air and carrying out the final heating in vacuum, followed by cooling in a neutral gas, eliminates the possibility of decarburizing the surface layer of the preforms. The method is reduced. It oxidizes its surface, improves metal degassing, and increases the accuracy of the drill blank. Calibration by crimping blanks on the outer diameter in the temperature ranges of structural transformations increases the operational properties of the tool. The invention The method of manufacturing a tool of high-speed steel, including heating to rolling temperature, rolling, heating, hardening, cooling and straightening, with the aim of improving the quality of the tool, heating up and cooling up to 950-1050С in vacuum, cooling 250–400 ° C with an inert gas, and the subsequent cooling is carried out in air in a fixed state. 6 Sources of information taken into account in the examination 1. Sat. Works VNII tool. M- 562, issue. I, 2, p. 45-46. 2. Creation of equipment and development of dressing modes after rolling the billets of drills 10-14 mm with a tapered and cylindrical shank. Report VNIIinstrument. 1971. p. 28-30.