CS231938B1 - Method of making high speed steel tools - Google Patents

Abstract

The invention relates to a method of producing tools from high-speed steel by drop forging, for example cutting inserts for lathe knives from a blank. The essence of the invention lies in the fact that first an unsintered molding made from high-speed steel powders is heated in a furnace with a protective neutral atmosphere to a forging temperature of 900 to 1,200 °C. The molding is then forged into the desired shape in a die.

Description

of high-speed steel by die forging, for example, turning inserts from a blank. SUMMARY OF THE INVENTION The principle of the invention is that a non-sintered compact made of high-speed steel powders is first heated in a furnace with a protective neutral atmosphere to a brazing temperature of 900 to 1200 ° C.

The die is then forged to the desired shape.

331938 2

The invention relates to a method for producing high-speed steel tools by die forging, for example, turning inserts from a blank.

In the current technological process of production of forgings from powder metallurgy semifinished products, the first is made from powders of the compact, which is sintered in the next operation. Sintering results in an initial forging blank. This blank generally has a low density and, as a consequence, a lower desired mechanical properties. Upon heating to the forging temperature, the desired forging of the workpiece occurs by subsequent forging of the workpiece, the plastic deformation bringing the structure to a level close to the theoretical value, whereby the forging also obtains the desired mechanical and other, for example, technological properties. The disadvantage of the present process is the higher energy consumption and laboriousness resulting from the double heating of the blank during the sintering of the compact and then during the forging itself.

These drawbacks are overcome by the method according to the invention intended for the production of high-speed steel tools by die forging, e.g. SUMMARY OF THE INVENTION The principle of the invention is to first heat a non-sintered compact made of high-speed steel powder in a furnace with a protective neutral atmosphere to a forging temperature of 900 to 1200 ° C. The die is then forged to the desired shape.

By this process, a homogeneous structure of β with uniformly distributed carbides is achieved, without a radish with a density very close to that of the steel produced by the classical metallurgical process. The resulting cutting properties and durability are the same or better compared to conventional steel, achieving a 50% weight saving of steel and, in particular, saving heat energy for heating by eliminating heating to a temperature of 1100 ° C in the process.

Example

Process for making square cutting inserts from high-speed tungsten-molybdenum steel. The plate blank is cold pressed from powders by a composition corresponding to said steel to dimensions of 48.6 x 18.6 x 10.3 mm. The stock density is 75% of that of the metallurgically produced corresponding steel. The blank is then heated in an argon atmosphere furnace to a temperature of 1,140 ° C with a temperature of 3 min. Then the blank is forged in a closed die to the final desired shape of the cutting insert, which has a chipbreaker formed on its forehead. The dimensions of the plate are 19.1 x 19.1 x 7.7 mm. The resulting plate density is 99.8%.

SUBJECT OF THE INVENTION

Claims (1)

Method for producing high-speed steel tools by drop forging, for example, turning inserts of a blank, characterized in that the non-sintered compact made of high-speed steel powders is heated in a furnace with a protective neutral atmosphere to a forging temperature of 900 to 1200 ° C. die forging to the desired shape.