SU1761365A1 - Shaft forging method - Google Patents

Abstract

Usage: metal forming, forging large forgings of responsible purpose. Summary of the invention: in one of the ingots, the melting of the axial bore is pierced with a hollow piercing, starting from profit, the otter metal is checked for the presence and location of defects in it. An otter is stretched into a stepped sample, each step of which corresponds to steps. The invention relates to the processing of metals by pressure, in particular to the forging of large forgings of a responsible purpose, and can be used in heavy and power engineering. The aim of the present invention is to increase the yield of the product and improve the quality of the product by eliminating defects in the axial zone and rational cutting of ingots. FIG. 1 shows the original ingot; in fig. 2 - ingot after the shaft. Then re-check the metal sample. Defect-free areas are determined in it, incl. y (in profit and y) at the bottom of the ingot and the thermomechanical parameters of forging required for welding defects. After that, the ingot is drawn until the axial bore is closed, and when the profitable and bottom parts are removed, the defect-free part of the profit and / or the bottom part, equal to the mass of the otter, is left in the forging. When the remaining ingots are melted, the thermomechanical parameters determined on the sample are used. And when marking the forgings and removing the profitable and bottom parts of the ingots in the forgings, the sections corresponding to the length of the defect-free sample areas at the profit and / or bottom of the ingot are left in the forgings; before the ingot is pierced, it is deposited to the ratio of the diameter to the height of not more than 3; the pierced ingot is drawn through the mandrel. 3 h.p-f-ly, 5 ill. precipitation and otter, obtained after the ingot firmware; in fig. 3 test after drawing; in fig. 4 - shaft after preliminary drawing on the mandrel; in fig. 5, forging the shaft after drawing to the final dimensions, forging the hole and removing part of the profit and, the bottom of the ingot. The method is carried out as follows. A batch of ingots of one heat is heated in a furnace up to forging temperature. Then, one of the ingots of smelting is upset to the ratio D / N of not more than XJ o 00 o C

Description

3. Sew through the hole with hollow stitches. Then the stitching is removed from the otter and transferred to the latter for further processing.

An otter obtained after flashing is controlled (for example, UT) with fixing the size and location of defects, especially at / in the profitable and at / bottom parts of the ingot. After control, the otter is heated and drawn into the strikers to the sample with steps corresponding to the shaft steps. Then, the control of the metal of the coffin is carried out. The defect-free sample zones and the appropriate cutting of the ingot (bottom removal or profit) are finally determined by marking the shaft forging. In ingots of various designs, casting and cooling conditions, either the bottom or the profitable part may be more defective.

In the case of smooth shafts, the otter is pulled one step corresponding to the diameter of the shaft.

According to the results of the final control of the sample, optimal thermomechanical parameters are set for welding ingot defects.

Said stitched ingot is first drawn on the mandrel, marking along the length (based on the sample metal data), and then drawn to the dimensions of the shaft with the forging of the hole obtained by flashing and chopping the excess from the bottom and profitable parts of the ingot. Left part of the profit or / and bottom in the body forgings by weight, equal to the mass of the otter.

The remaining ingots are drawn to forging sizes with the observance of the optimal forging parameters obtained from the results of the sample passing. Based on the same results, rational cutting of the ingot was carried out (i.e., taking into account the quality of the metal profit and the bottom of the ingot), shifting the forging to the bottom or profitable part of the ingot and discarding the defective areas of the latter.

Example. Made a batch of forgings of stepped shafts (turbine shaft К-1000-65Л500-2) from steel 25Х2НМФА on the press 150 Mn,

The half-year production program is 12 pieces. The weight of the forging is 50 tons, the weight of the ingot is 101 tons.

The forging of the shank has the diameters of the steps 1550; 1360; 1100;

0

five

0

five

0

five

0

45

five

1500 mm and the length of the steps, respectively, 850; 460; 500; 90 mm.

The first ingot of a batch weighing 101 tons (with a D / H ratio of 1.0) was heated to a forging temperature of 1230 HP. In the first removal, it was billetted to a diameter of 2100 mm (diameter of the bottom part of the ingot) and a block was cut down with a length of 2800 mm, leaving 200 mm profitable and all the bottom part of the ingot in the forging. In the second removal, the ingot was heated to 1230 ° C and set down to a height of 1500 mm and a diameter of 3000 mm. From the side of profit, a hollow piercing was installed with a diameter of 550,270 mm and sewed an axial hole with it to produce an otter with a diameter of 270 mm and a length of 1500 mm.

Then the otter was handed over for machining and ultrasonic testing. The main number of defects was found in the profit zone of the ingot, 1/3 of the otter's height. After checking and fixing the defects, the otter was heated to a temperature and pulled in combined strikers on a 1.5 Mn press with relative feeds of 0.5–1.0 per stepped forging “Steps were selected with notes, respectively, 5, and. What. corresponded to the hooks on three steps of the shank. After stretching, a sample was obtained with steps with a diameter of 130, 115, 95 mm. Carried out the control. The UZK data after forging, macro- and microscopic examination of the metal showed the absence of any discontinuities and other defects after the stretch. That spoke about the sufficiency of ukova A for welding defects in the axial zone. A defect appeared to be a section of 200 mm in length, immediately adjacent to the otter's end on the profit side of the ingot.

After flashing, the first ingot was first produced on mandrels with a diameter of 50 and 200 mm, and then without a mandrel.

In the third offset, a step with a larger diameter mm and a length of 850 mm and a second step with a diameter of 1550 mm and a length of 1) 60 mm from the bottom part of the ingot were made out on a mandrel with a diameter of 50 mm.

In the fourth extension, steps with a diameter of 1150 and 1550 mm

5 1

and in the fifth, without a mandrel, the final stretch of the steps with a diameter of 1360, 1100 and 1500 mm, respectively, 500 and 90 mm long, was carried out, a full marking of the forging along the length and cutting of the surplus with the inclusion of a part (100 mm in length) of the body forgings; The bottom part of the ingot was not removed at all, since it was completely usable by UZK and not affected by cords of eccentric segregation.

The remaining batch of ingots in the amount of 11 pieces. forged in compliance with the thermomechanical parameters of forging used in drawing otters and the first ingot. In this case, all the forgings used fully bottom part of the ingots. After the ultrasonic inspection of 11 shafts made without an axial canal, all the forgings are recognized as valid.

In comparison with the known method of manufacturing shafts from ingots of one heat, the mass and design of the proposed

The invention allows to improve the quality of the product due to the elimination of defects in the axial zone and the rational cutting of ingots.

Claims (3)

1. A method of forging shafts, predominantly of the same stepped form, from ingots of one heat and weight, including the alternation of heating and broaching operations for each of the ingots, several markings, marking of the forging, shaping of the shaft steps and its chipping, characterized in that yield and improve the quality of products. by eliminating the defects of the axial zone and rational cutting of ingots, previously in one of the ingots of the melting, the axial bore is pierced with a hollow piercing from the profit to the bottom part of the ingot, the otter metal is monitored 15 0 25 thirty 35 40 the location and location of defects in it, then the otter is drawn to obtain a sample, each step of which corresponds to shaft steps, after which the metal is checked again and defect-free areas and thermomechanical parameters of forging are determined, the forging limits are shifted to the bottom or profitable part m, when marking it in an ingot, the defect-free area is arranged on the length of the stepped sample, and defective parts of the profit and / or bottom are removed during the cutting. 2. Method according to claim, characterized in that the ingot is sedimented before piercing to a ratio of diameter to height of not more than 3. 3. A method according to claim 1, characterized in that the stitched ingot is pulled until the axial bore is closed, and when forged, the forgings leave a defect-free part from the profit and / or bottom part with a mass equal to the mass of the otter. k. Way pop. 1 and 3, characterized in that prior to stretching a hollow ingot with closing the axial bore, a stitched ingot is preliminary drawn over the mandrel. .3 fit / 8, f Fie.2 phage fae.5