SU840160A1 - Method of thermal straightening of thin sheet high strength steel rolled stock - Google Patents

Description

54) METHOD OF THERMORICING OF THIN SHEET ROCKS FROM HIGH-STRENGTH STEELS

I

The invention relates to mechanical engineering, mainly compressor, and can be used in the manufacture of flat elastic elements, such as compressor membranes, made from rolled sheets.

There are known methods for eliminating non-flatness by heating blanks 1 between the plates.

However, due to the uneven transfer of compression pressure during assembly, heating, and cooling, the elimination of the non-planarness is incomplete.

The closest in technical essence and the achieved result is the method of thermogrowing of sheet material, which consists in the fact that the blank sheets are packed in bags, displaced between the intermediate plates,. suitably machined to high flatness, and supporting plates, apply pressure, compressing the bag, heat, cool and disassemble the f 23 Process disadvantages — the need to pretreat intermediate plates, whose thickness is 0.25-0.5 mm, for high flatness, hardness and surface cleanliness, which makes it impossible to apply this method of thermal straining for products from thin-rolled products of high-strength materials with a yield strength of more than 60 kgf / mm.

The purpose of the invention is to improve the flatness of thin-sheet rolled parts of high-strength steels.

The goal is achieved by the method of thermal sheeting of thin-sheet material, in which the blanks are gathered into a bag, stirred between the support plates, applied DEFENERATION is heated, held and cooled, the solution is applied, creating tensile strength in the blanks, and heated to relaxation temperatures high stresses 47 ° 550 ° C.

 When pressure is applied, compression of the workpieces occurs with the improvement of military races. These factors cause the elimination of non-stability, the subsequent heating of the temperature of the elastic stresses to the rocket, ensuring the preservation of the high flatness obtained during assembly.

Thus, the proposed method makes it possible to eliminate the flatness of billets from thin-sheet rolled steel of high-strength steels without the use of labor-intensive in the manufacture of intermediate plates of high flatness, hardness and surface finish.

The stamp that allows the proposed method to be implemented consists of base plates, the bottom one with a protrusion and the top with a hollow. The dimensions of the protrusion and depression depend on the required dimensions of the product. By means of such a relief of the stamp in the blanks, when the pressure is applied to them, tensile stresses are created.

Approx. Billets with a diameter of 320 mm made of a tape with a thickness of 0.4 mm made of 09H15N8Y stainless steel with a yield strength of 87 kgf / mm are packed into a bag and stirred between the support plates, the bottom of which has a protrusion with a diameter of 290 mm and a height of 8 mm. diameter 29 (3 mm and height 5 mm.

Apply pressure to the plates by uniformly tightening the bolts during. whose upper plate annularly presses against the free edges of the blanks, crimping them around the protrusion on the lower support plate, thereby creating tension in the blanks. The plates are brought together until the gap between the edges of the bag and the bottom plate is 3 mm. After pressure is applied, the preforms are heated to and

incubated at this temperature for 30 minutes. The bag is then cooled to room temperature and the blanks removed from the die.

Non-flatness is assessed by a watch-type indicator. The magnitude of the flatness (the difference between the peripheral and central zones) does not exceed 1 mm with the diameter of the finished membrane of 290 mm; in the case as before the heat rejection, the flatness of the blanks was 4-O mm.

The proposed method of thermal sheeting of thin-rolled steel assists the radiation of high flatness for high-strength steel products, eliminates the need to manufacture special intermediate plates of high hardness and flatness, and also increases the operational durability of thin-rolled steel parts of high-strength steels, in particular membrane compressor membranes.

Claims (2)

Invention Formula The method of thermal rolling of sheet steel from high-strength steels, in which the blanks are gathered into a package, placed between the support plates, pressure is applied, heated, maintained and cooled, characterized in that, with the purpose of increasing the blanks, a tensile force is applied to them simultaneously heating is carried out up to 470-550 C. Sources of information taken into account in the examination 1.Kamenichny I. S Handbook of Thermist. Kiev, Mashgiz, 1954, - p. 144 2. The author's testimony of the USSR № 352953, cl. From 21D to 9/06, 1972.