CN103484636A - Production process of forged tee - Google Patents

Abstract

The invention provides a production process of a forged tee. The production process mainly comprises the steps of pouring and forging molten steel into forging stocks, thermally processing the forging stocks into workblanks, further forging the workblanks, rapidly cooling and normalizing the workblanks, and finally air cooling and tempering the workblanks, and preserving the temperature. Through the steps, the forged tee can be obtained. The yield strength Rel and the tensile strength Rm of the forged tee obtained through the production process are 50 to 70MPa higher than that of the technical requirement, and the mechanical property requirement can be met; the composition is P+B+F, the grain size is grade 5 to grade 6, and the technical requirements can be met. By adopting the rapid cooling and normalization, the mechanical property of the forged tee is proved in the test to be remarkably improved, both the grain size and the composition meet the requirement, and the production process is particularly suitable for producing the F22 forged tee.

Description

A kind of production technique of forging threeway

Technical field

The invention belongs to thermal treatment manufacturing technology field, be specifically related to a kind of production technique of forging threeway.

Background technology

The forging threeway of now producing, technical requirements is: yield strength Rel >=310MPa, tensile strength Rm >=515MPa, unit elongation A >=20%, relative reduction in area Z >=30%, normal temperature impacts Akv >=27J, metallographic structure is perlite (P) or bainite (B)+ferrite (F), grain fineness number >=4 grade.Normalizing is difficult to meet the mechanical property requirement as requested, even take the air blast blast-cold, performance also can't guarantee; If modifier treatment can meet the mechanical property requirement, but can't meet the requirement that metallographic structure is perlite (P)+ferrite (F).

Summary of the invention

For solving the problems of the technologies described above, the invention provides a kind of production technique of forging threeway.

The production technique of forging threeway of the present invention mainly comprises the steps:

Step (1) adopts the electric arc furnace smelting molten steel, after vacuum outgas, is poured in ingot mold, obtains steel ingot;

Step (2) steel ingot, through 1200-1250 ℃ of heat, is forged into forging stock with press by steel ingot;

Step (3) forging stock, after forging postheat treatment, is processed into blank;

Step (4) is heated to 700-750 ℃ by blank with≤60 ℃/h, and insulation 2-4 hour, then be heated to 940-960 ℃ with≤80 ℃/h, is incubated after 7-9 hour the quick cooling normalizing of coming out of the stove;

The quick cooling normalizing of step (5), the air cooling 2-4 minute that comes out of the stove, water-cooled 15-25 second, then air blast is chilled to below 200 ℃;

Step (6) is heated to 600-650 ℃ by the blank after air-cooled end with≤60 ℃/h, after tempering insulation 14-18h, with≤30 ℃/h stove, is chilled to below 300 ℃ and comes out of the stove, and obtains described forging threeway.

The beneficial effect of production technique of the present invention:

1, yield strength Rel and tensile strength Rm all exceed technical requirements 50-70MPa, can meet its mechanical property requirement;

2, be organized as P+B+F, grain fineness number 5-6 level, meet technical requirements.

Evidence, step of the present invention (5) adopts quick cooling normalizing to significantly improve to forge the mechanical property of threeway, and grain fineness number and organizing all meets the requirements, and is particularly suited for producing F22 and forges threeway.

Embodiment

The quick cooling normalizing process of embodiment 1

Step (1) adopts the electric arc furnace smelting molten steel, after vacuum outgas, is poured in ingot mold, obtains steel ingot;

Step (2) steel ingot, through 1200 ℃ of heat, is forged into forging stock with press by steel ingot;

Step (3) forging stock, after forging postheat treatment, is processed into blank;

Step (4) is heated to 700 ℃ by blank with≤60 ℃/h, is incubated 4 hours, then with≤80 ℃/h, is heated to 960 ℃, the quick cooling normalizing of coming out of the stove after being incubated 7 hours;

The quick cooling normalizing of step (5), the air cooling 2 minutes of coming out of the stove, water-cooled 25 seconds, then air blast is chilled to below 200 ℃;

Step (6) is heated to 600 ℃ by the blank after air-cooled end with≤60 ℃/h, after tempering insulation 18h, with≤30 ℃/h stove, is chilled to below 300 ℃ and comes out of the stove, and obtains described forging threeway.

The quick cooling normalizing process of embodiment 2

Step (1) adopts the electric arc furnace smelting molten steel, after vacuum outgas, is poured in ingot mold, obtains steel ingot;

Step (2) steel ingot, through 1250 ℃ of heat, is forged into forging stock with press by steel ingot;

Step (3) forging stock, after forging postheat treatment, is processed into blank;

Step (4) is heated to 750 ℃ by blank with≤60 ℃/h, is incubated 2 hours, then with≤80 ℃/h, is heated to 940 ℃, the quick cooling normalizing of coming out of the stove after being incubated 9 hours;

The quick cooling normalizing of step (5), the air cooling 4 minutes of coming out of the stove, water-cooled 15 seconds, then air blast is chilled to below 200 ℃;

Step (6) is heated to 650 ℃ by the blank after air-cooled end with≤60 ℃/h, after tempering insulation 14h, with≤30 ℃/h stove, is chilled to below 300 ℃ and comes out of the stove, and obtains described forging threeway.

The common normalizing process of embodiment 3

Step (1) rises to 700-750 ℃ of insulation 2-4 hour by the gained blank with≤60 ℃/h;

Step (2) then rises to 940-960 ℃ of insulation 7-9 hour with≤80 ℃/h;

The common normalizing of step (3), the air blast of coming out of the stove is chilled to below 200 ℃;

Step (4) is heated to the blank after air-cooled end to be chilled to below 300 ℃ and to come out of the stove with≤30 ℃/h stove after 600-650 ℃ of tempering insulation 14-18h with≤60 ℃/h

the performance comparison of various processes:

The forging threeway performance that common normalizing process (embodiment 3) makes is as follows:

The forging threeway performance that quick cooling normalizing process (embodiment 1) makes is as follows:

Contrast above-mentioned two techniques, quick cooling normalizing can significantly improve its mechanical property, and grain fineness number and organizing all meets the requirements.Visible, quick cooling normalizing can meet performance and organize requirement.

Claims (1)

1. a production technique of forging threeway, is characterized in that, mainly comprises the steps:

Step (1) adopts the electric arc furnace smelting molten steel, after vacuum outgas, is poured in ingot mold, obtains steel ingot;

Step (2) steel ingot, through 1200-1250 ℃ of heat, is forged into forging stock with press by steel ingot;

Step (3) forging stock, after forging postheat treatment, is processed into blank;

Step (4) is heated to 700-750 ℃ by blank with≤60 ℃/h, and insulation 2-4 hour, then be heated to 940-960 ℃ with≤80 ℃/h, is incubated after 7-9 hour the quick cooling normalizing of coming out of the stove;

The quick cooling normalizing of step (5), the air cooling 2-4 minute that comes out of the stove, water-cooled 15-25 second, then air blast is chilled to below 200 ℃;

Step (6) is heated to 600-650 ℃ by the blank after air-cooled end with≤60 ℃/h, after tempering insulation 14-18h, with≤30 ℃/h stove, is chilled to below 300 ℃ and comes out of the stove, and obtains described forging threeway.