CN103071970A - Forging method for intermediate shafts for transmissions - Google Patents

Abstract

The invention discloses a forging method for intermediate shafts for transmissions, which includes the following steps: a cylindrical billet is cast, and the percentages by weight of chemical components in the cylindrical billet are as follows: 0.23 to 0.40 percent of C, 1.6 to 2.0 percent of Mn, 1.1 to 1.6 percent of Si, 0.07 to 0.15 percent of Te, 0.2 to 2.0 percent of Cr, 0.42 to 0.83 percent of W, 0.4 to 1.0 percent of Zr, 0.4 to 0.50 percent of Cu, 0.040 percent or less of P and 0.030 percent or less of S; the temperature of the cast billet is decreased to 300 DEG C, then heated to 650 DEG C to 760 DEG C and kept for 3 to 5 hours, the furnace is cooled to be 300 DEG C, and the temperature is kept for 4 hours, then heated to 650 DEG C to 760 DEG C, kept for 17 hours, cooled to 450 DEG C at 50 DEG C per hour and then cooled to 140 DEG C at 20 DEG C per hour. The forging method is favorable for mass industrial production, the phenomena of inclusions and insufficient filling in the process of forging are reduced, the mechanical properties of the products are further improved, product material is saved, and the service life of the product mold is prolonged.

Description

Speed changer jackshaft forging method

Technical field

The present invention relates to a kind of speed changer jackshaft forging method.

Background technology

At present, produce the speed changer jackshaft, its production technology is as follows:

A, selection raw material;

B, blanking;

C, be heated to 1150-1230 ℃;

D, the blank after will heating directly forge cool to room temperature in the air after being put into pulling on the pneumatic hammer, round as a ball, shaping with movable loose tool at pneumatic hammer;

E, lathe roughing;

F, modified heat treatment;

G, lathe fine finishining;

H, finished product.

Above-mentioned technology has the following disadvantages:

1, large batch of product is large with labor intensity of operating staff, and product quality is inappropriate this technique of using entirely with manual control, labour-intensive technology, and production efficiency is very low;

2, because the pneumatic hammer blow energy is little, it is inadequate that forging is full of power, can not forge the shrinkage pool of holder wire clamp, and the forging products dimensional tolerance is very large.

Summary of the invention

The purpose of this invention is to provide a kind of speed changer jackshaft forging method, make it be beneficial to large batch of industrialized production, and reduced the phenomenon that occurs the folder dirt in the forging process, is not fully filled, the mechanical property of product is further improved, save product materials, improved the die life of product.

Technical scheme of the present invention is as follows:

Speed changer jackshaft forging method may further comprise the steps:

A, cast cylinder blank step

Chemical component weight percentage is in the cylinder blank: C 0.23-0.40%, Mn 1.6-2.0%, Si 1.1-1.6, Te 0.07-0.15%, Cr 1.2-2.0%, W 0.42-0.83%, Zr 0.4-1.0%, Cu 0.4～0.50%, P≤0.040%, S≤0.030%, and surplus is Fe and inevitably is mingled with matter; The base substrate temperature of moulding by casting is down to 300 ℃, is heated to 650-760 ℃ again, is incubated 3-5 hour, and stove is chilled to 300 ℃, is incubated 4 hours, is heated to 650-760 ℃ again, is incubated 17 hours, is cooled to 450 ℃ with 50 ℃/hour, again with 20 ℃/hour, is cooled to 140 ℃;

B, forging step

1, selecting diameter is the 32mm round steel, utilizes cutter to carry out blanking, blank length 142.6mm after shearing;

2, the blank of step 1 is put into the intermediate-frequency heating furnace heating, heating-up temperature 1120-1180 ℃, kept 3.8min heat time heating time;

3, the workpiece other end after will heating is put into punch press and is carried out jumping-up, jumping-up thickness 140 0-3mm;

4, the upset end in the workpiece is carried out heading, so that upset end must be grown 10 0-2mm, wide 32 ± 0.5mm;

5, the workpiece after will the side of pressure is put into the press that rubs, and is installed in mould in the press that rubs, and utilizes mould forge hot workpiece; 850 ℃ of temperature, pressure 400T;

With the workpiece after the forge hot, put into that punch press is cut edge, hot school processes;

C, with the heat treatment of workpieces behind the hot school

The jackshaft of forging molding is placed the glowing furnace of the first design temperature, the first design temperature is 800 ℃-900 ℃, keep in the glowing furnace temperature that jackshaft is implemented to quench, the temperature retention time scope is 2.2-2.8 hour, and the jackshaft after the heating of quenching is come out of the stove is cooled to temperature≤200 ℃;

Cooled jackshaft is placed the tempering furnace of the second design temperature, and the second design temperature is 560 ℃-600 ℃, keeps in the tempering furnace temperature that jackshaft is implemented tempering, and the temperature retention time scope is 3.2-4.3 hour, with the cooling of coming out of the stove of the jackshaft after the tempering heating;

D, with the workpiece Shot Blasting after the heat treatment;

E, with the piece packaging of Shot Blasting.

Described heat treatment of workpieces:

The jackshaft of forging molding is placed the glowing furnace of the first design temperature, the first design temperature is 850 ℃, keep in the glowing furnace temperature that jackshaft is implemented to quench, the temperature retention time scope is 2.5 hours, and the jackshaft after the heating of quenching is come out of the stove is cooled to temperature≤200 ℃;

Cooled jackshaft is placed the tempering furnace of the second design temperature, and the second design temperature is 580 ℃, keeps in the tempering furnace temperature that jackshaft is implemented tempering, and the temperature retention time scope is 3.8 hours, with the cooling of coming out of the stove of the jackshaft after the tempering heating.

The present invention makes it be beneficial to large batch of industrialized production, and has reduced the phenomenon that occurs the folder dirt in the forging process, is not fully filled, and the mechanical property of product is further improved, and has saved product materials, has improved the die life of product.

Of the present invention PowerPerformance detection data is as follows:

Tensile strength 〉=924 Mpa

Yield strength 〉=792 Mpa

Percentage elongation 〉=14%

The contraction percentage of area 〉=45%

Brinell hardness HB=237-269.

Description of drawings

Fig. 1 is the metallographic structure figure of jackshaft limit section.

Fig. 2 is middle axle center part metallographic structure figure.

The specific embodiment

Speed changer jackshaft forging method may further comprise the steps:

A, cast cylinder blank step

Chemical component weight percentage is in the cylinder blank: C 0.23-0.40%, Mn 1.6-2.0%, Si 1.1-1.6, Te 0.07-0.15%, Cr1.2-2.0%, W 0.42-0.83%, Zr 0.4-1.0%, Cu 0.4～0.50%, P≤0.040%, S≤0.030%, and surplus is Fe and inevitably is mingled with matter; The base substrate temperature of moulding by casting is down to 300 ℃, is heated to 650-760 ℃ again, is incubated 3-5 hour, and stove is chilled to 300 ℃, is incubated 4 hours, is heated to 650-760 ℃ again, is incubated 17 hours, is cooled to 450 ℃ with 50 ℃/hour, again with 20 ℃/hour, is cooled to 140 ℃;

B, forging step

1, selecting diameter is the 32mm round steel, utilizes cutter to carry out blanking, blank length 142.6mm after shearing;

2, the blank of step 1 is put into the intermediate-frequency heating furnace heating, heating-up temperature 1120-1180 ℃, kept 3.8min heat time heating time;

3, the workpiece other end after will heating is put into punch press and is carried out jumping-up, jumping-up thickness 140 0-3mm;

4, the upset end in the workpiece is carried out heading, so that upset end must be grown 10 0-2mm, wide 32 ± 0.5mm;

5, the workpiece after will the side of pressure is put into the press that rubs, and is installed in mould in the press that rubs, and utilizes mould forge hot workpiece; 850 ℃ of temperature, pressure 400T;

With the workpiece after the forge hot, put into that punch press is cut edge, hot school processes;

C, with the heat treatment of workpieces behind the hot school

The jackshaft of forging molding is placed the glowing furnace of the first design temperature, the first design temperature is 850 ℃, keep in the glowing furnace temperature that jackshaft is implemented to quench, the temperature retention time scope is 2.5 hours, and the jackshaft after the heating of quenching is come out of the stove is cooled to temperature≤200 ℃;

Cooled jackshaft is placed the tempering furnace of the second design temperature, and the second design temperature is 580 ℃, keeps in the tempering furnace temperature that jackshaft is implemented tempering, and the temperature retention time scope is 3.8 hours, with the cooling of coming out of the stove of the jackshaft after the tempering heating;

D, with the workpiece Shot Blasting after the heat treatment;

E, with the piece packaging of Shot Blasting.

Claims (2)

1. speed changer jackshaft forging method is characterized in that, may further comprise the steps:

A, cast cylinder blank step

Chemical component weight percentage is in the cylinder blank: C 0.23-0.40%, Mn 1.6-2.0%, Si 1.1-1.6, Te 0.07-0.15%, Cr 1.2-2.0%, W 0.42-0.83%, Zr 0.4-1.0%, Cu 0.4～0.50%, P≤0.040%, S≤0.030%, and surplus is Fe and inevitably is mingled with matter; The base substrate temperature of moulding by casting is down to 300 ℃, is heated to 650-760 ℃ again, is incubated 3-5 hour, and stove is chilled to 300 ℃, is incubated 4 hours, is heated to 650-760 ℃ again, is incubated 17 hours, is cooled to 450 ℃ with 50 ℃/hour, again with 20 ℃/hour, is cooled to 140 ℃;

B, forging step

1), to select diameter be the 32mm round steel, utilizes cutter to carry out blanking, blank length 142.6mm after shearing;

2), the blank of step 1 is put into intermediate-frequency heating furnace heating, heating-up temperature 1120-1180 ℃, keep 3.8min heat time heating time;

3), the workpiece other end after will heating is put into punch press and is carried out jumping-up, jumping-up thickness 140 0-3mm;

4), the upset end in the workpiece is carried out heading, so that upset end must be grown 10 0-2mm, wide 32 ± 0.5mm;

5), the workpiece after will the side of pressure puts into the press that rubs, and is installed in mould in the press that rubs, and utilizes mould forge hot workpiece; 850 ℃ of temperature, pressure 400T;

6), with the workpiece after the forge hot, put into that punch press is cut edge, hot school processes;

C, with the heat treatment of workpieces behind the hot school

The jackshaft of forging molding is placed the glowing furnace of the first design temperature, the first design temperature is 800 ℃-900 ℃, keep in the glowing furnace temperature that jackshaft is implemented to quench, the temperature retention time scope is 2.2-2.8 hour, and the jackshaft after the heating of quenching is come out of the stove is cooled to temperature≤200 ℃;

Cooled jackshaft is placed the tempering furnace of the second design temperature, and the second design temperature is 560 ℃-600 ℃, keeps in the tempering furnace temperature that jackshaft is implemented tempering, and the temperature retention time scope is 3.2-4.3 hour, with the cooling of coming out of the stove of the jackshaft after the tempering heating;

D, with the workpiece Shot Blasting after the heat treatment;

E, with the piece packaging of Shot Blasting.

2. speed changer according to claim 1 jackshaft forging method is characterized in that: described heat treatment of workpieces:

The jackshaft of forging molding is placed the glowing furnace of the first design temperature, the first design temperature is 850 ℃, keep in the glowing furnace temperature that jackshaft is implemented to quench, the temperature retention time scope is 2.5 hours, and the jackshaft after the heating of quenching is come out of the stove is cooled to temperature≤200 ℃;

Cooled jackshaft is placed the tempering furnace of the second design temperature, and the second design temperature is 580 ℃, keeps in the tempering furnace temperature that jackshaft is implemented tempering, and the temperature retention time scope is 3.8 hours, with the cooling of coming out of the stove of the jackshaft after the tempering heating.

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