CN1759976A

CN1759976A - Technique for producing 55CrSi bull rod steel

Info

Publication number: CN1759976A
Application number: CNA2004100853405A
Authority: CN
Inventors: 叶建松; 林宪; 余国松; 吴小良; 王文桂; 周引
Original assignee: Hangzhou Iron & Steel Group Co
Current assignee: Hangzhou Iron & Steel Group Co
Priority date: 2004-10-11
Filing date: 2004-10-11
Publication date: 2006-04-19
Anticipated expiration: 2024-10-11
Also published as: CN100478124C

Abstract

A technology for producing coiled 55CrSi steel rod includes such steps as preparing raw materials, smelting in electric furnace, refining outside furnace, vacuum degassing, conticasting, rolling and coiling. Its advantages are simple process, low energy consumption and high productivity and quality of product.

Description

55CrSi wire rod steel production technology

Technical field

The invention belongs to the refining of metal technical field, particularly relate to a kind of 55CrSi wire rod steel production technology.

Background technology

In the prior art, the 55CrSi wire rod steel is a quality material of making automotive suspension spring, its quality and performance also can be used as the making raw material that requires high engine cylinder valve spring, usually employing is got the raw materials ready, the production method of converter smelting, external refining, vacuum outgas, die casting, blooming mill cogging, high speed wire rolling and wire rod obtains this product greatly, produce blank owing to take die casting, need to reheat blank in the subsequent handling,, belong to two pyrogene materials by the blooming mill cogging; And cogging need reheat, and then consumed energy is bigger; Cogging simultaneously needs certain production time, thereby has extended the production cycle; Owing to metal consumption is in various degree arranged during cogging,, has increased production cost so reduced finished product rate.

Summary of the invention

The object of the present invention is to provide that a kind of technology is simple, energy consumption is low, the 55CrSi wire rod steel production technology of low equipment investment, production efficiency height, good product quality.

The present invention seeks to adopt such process to realize:

55CrSi wire rod steel production technology is characterized in that comprising following operation: get the raw materials ready, the AF electric furnace smelting) LF external refining, VD vacuum outgas, CCM continuous casting, high speed wire rolling and wire rod.

Procedure for preparation is that material is prepared before the steel-making, and it comprises the content of three aspects: the one, increase the ratio of the pig iron in feed stock for blast furnace, and the harmful residual elements total amount of control is in 0.25%; Next is to determine that every stove steel configuration hot metal ratio is 30～40%; The 3rd, keep all steel-making raw material drying, alloy is gone into the bag baking;

EAF electric furnace smelting operation is to make the preceding carbon content of tapping 〉=0.20%, tapping back carbon content 〉=0.30%; Make water-cooled carbon oxygen lance spray carbon amount 〉=6kg/T: nitrogen content is controlled at below the 80ppm; Carbon content before the tapping 〉=0.20%, tapping back carbon content 〉=0.30%; Do not add and contain aluminium deoxidizer, adopt no aluminium to hang down S, P ferrochrome, ferromanganese, ferrosilicon; Tapping temperature is controlled at 1600～1660 ℃.

LF external refining operation: refining time is 30～60 minutes, adjusts chemical composition with no aluminium alloy, and soft mixing time was greater than 3 minutes, and to promote to be mingled with come-up, refining every stove molten steel in latter stage is fed 200～400 meters on CaSi line, and tapping temperature is controlled at 1610～1650 ℃.

VD vacuum outgas operation: adopt carbon deoxidation under the vacuum, be not less than 10 minutes in the following retention time of condition of high vacuum degree, the control hydrogen content is not more than 2ppm, and tapping temperature is controlled at 1520～1560 ℃.

CCM continuous casting working procedure content: the continuous casting section is set to 150mm * 150mm; Implement total process protective casting; Open the crystallizer electromagnetic agitation; The target degree of superheat is less than 30 ℃, and is weak cold; Connect and to water the stove number less than 7 stoves, one waters in time last stove the Bao Liugang amount more than 10 tons; Pulling rate is 1.8～3.0m/min.

High speed wire rolling operation: continuous casting billet is carried out total ball blast,, defective continuous casting billet is carried out reconditioning handle by propping up by the face check; Single stove is rolling, must not organize and criticize; Start rolling temperature is 950～1050 ℃; Pre-final rolling temperature is 910～930 ℃; Subtracting the sizing temperature is 830～880 ℃; Laying temperature is 850～880 ℃; The stelmor travelling speed is 16～20m/min; Stay-warm case 1A～3A opens; Blower fan leaves 30～60% 1～No. 2, and all the other are closed.

Wire rod: be the finished product that the 55CrSi bar steel that the high speed wire rolling operation is obtained is turned to plate-like.

The present invention compared with prior art owing to adopt the continuous casting manufacturing technique blank to need not to reheat cogging, belongs to one-heating forming, save the cogging operation, shortened the production cycle, improved finished product rate, reduce production cost, and can guarantee the quality in kind of product.

The specific embodiment

Present embodiment according to get the raw materials ready, EAF electric furnace smelting, LF external refining, VD vacuum outgas, CCM continuous casting, high speed wire rolling and wire rod operation smelt the 55CrSi wire rod steel, chemical compositions such as the contained CrSi of this 55CrSi wire rod steel are as follows:

55CrSi chemical component table wt%

C	Mn	Si	P	S	Cr
C	Mn	Si	P	S	Cr	0.50～0.60	0.50～0.80	1.20～1.60	≤0.030	≤0.030	0.50～0.80

Claims

1,55CrSi wire rod steel production technology is characterized in that comprising following operation: get the raw materials ready, AF electric furnace smelting, LF external refining, VD vacuum outgas, CCM continuous casting, high speed wire rolling and wire rod.

2,55CrSi wire rod steel production technology according to claim 1 is characterized in that described procedure for preparation comprises the content of three aspects: the one, increase the ratio of the pig iron in feed stock for blast furnace, and the harmful residual elements total amount of control is in 0.25%; Next is to determine that every stove steel configuration hot metal ratio is 30～40%; The 3rd, keep all steel-making raw material drying, alloy is gone into the bag baking.

3,55CrSi wire rod steel production technology according to claim 1 is characterized in that described EAF electric furnace smelting operation is to make the preceding carbon content of tapping 〉=0.20%, tapping back carbon content 〉=0.30%; Make water-cooled carbon oxygen lance spray carbon amount 〉=6kg/T; Nitrogen content is controlled at below the 80ppm; Carbon content before the tapping 〉=0.20%, tapping back carbon content 〉=0.30%; Do not add and contain aluminium deoxidizer, adopt no aluminium to hang down S, P ferrochrome, ferromanganese, ferrosilicon; Tapping temperature is controlled at 1600～1660 ℃.

4,55CrSi wire rod steel production technology according to claim 1, it is characterized in that described LF external refining operation: refining time is 30～60 minutes, adjust chemical composition with no aluminium alloy, soft mixing time was greater than 3 minutes, to promote to be mingled with come-up, refining every stove molten steel in latter stage is fed 200～400 meters on CaSi line, and tapping temperature is controlled at 1610～1650 ℃.

5,55CrSi wire rod steel production technology according to claim 1, it is characterized in that described VD vacuum outgas operation: adopt carbon deoxidation under the vacuum, be not less than 10 minutes in the following retention time of condition of high vacuum degree, the control hydrogen content is not more than 2ppm, and tapping temperature is controlled at 1540 ℃.

6,55CrSi wire rod steel production technology according to claim 1, it is characterized in that described CCM continuous casting working procedure content: the continuous casting section is set to 150mm * 150mm; Implement total process protective casting; Open the crystallizer electromagnetic agitation; The target degree of superheat is less than 30 ℃, and is weak cold; Connect and to water the stove number less than 7 stoves, one waters in time last stove the Bao Liugang amount more than 10 tons; Pulling rate is 1.8～3.0m/min.

7,55CrSi wire rod steel production technology according to claim 1 is characterized in that described high speed wire rolling operation: be meant continuous casting billet is carried out total ball blast, by propping up by the face check, defective continuous casting billet is carried out reconditioning handle; Single stove is rolling, must not organize and criticize; Start rolling temperature is 950～1050 ℃; Pre-final rolling temperature is 910～930 ℃; Subtracting the sizing temperature is 830～880 ℃; Laying temperature is 850～880 ℃; The stelmor travelling speed is 16～20m/min; Stay-warm case 1A～3A opens; Blower fan leaves 30～60% 1～No. 2, and all the other are closed.