CN102505094A

CN102505094A - Production method of large-scale 82B high-carbon hard wire rod

Info

Publication number: CN102505094A
Application number: CN2011103933187A
Authority: CN
Inventors: 吕刚; 戈春刚; 智建国; 屈文利; 李斌; 谭晓东
Original assignee: Baotou Iron and Steel Group Co Ltd
Current assignee: Baotou Iron and Steel Group Co Ltd; Inner Mongolia Baotou Steel Union Co Ltd
Priority date: 2011-12-02
Filing date: 2011-12-02
Publication date: 2012-06-20

Abstract

The invention provides a production method of a large-scale 82B high-carbon hard wire rod, and belongs to the field of metallurgy and metal materials. The steel comprises the following components in percentage by weight: 0.79-0.84% of carbon, 0.15-0.35% of silicon, 0.70-0.90% of manganese, more than 0.1% but less than 1.0% of chromium and vanadium, less than or equal to 0.008% of aluminum, less than or equal to 0.030% of phosphor, less than or equal to 0.030% of sulfur, and the balance of iron and irrevocable impurities. In the production process, the tapping temperature of converter melting is between 1,630DEG C and 1,650 DEG C, the refining time of an LF (ladle furnace) is between 30 minutes and 56 minutes, the deep-vacuum degassing time of a VD (vacuum degassing) furnace is more than 15 minutes, the continuous casting superheat degree is controlled at 20-32 DEG C, the casting speed is between 0.6m/min and 0.75m/min, the heating time of a heating furnace is more than 2 hours, and cooling-controlled rolling is carried out; and the rolling temperature is between 1,130DEG C and 1,170 DEG C, the rolling specification is phi 13mm and phi 15mm, the tensile strength of a wire material with the diameter phi of 13mm is more than or equal to 1,200MPa, the reduction of cross section is more than or equal to 30%, while the tensile strength of a wire material with the diameter phi of 15mm is more than or equal to 1,180MPa, and the reduction of cross section is more than or equal to 28 percent.

Description

A kind of working method of big specification 82B high-carbon Wire Rod

Technical field

Belong to metallurgy and metal material field.

Background technology

As far as big specification SWRH82B high-carbon Wire Rod, improve intensity and plasticity simultaneously can be conflicting, is difficult to realize.Though many manufacturers have carried out big quantity research to technologies such as smelting, continuous casting, rolling, controlled chilling, because of equipment, raw material, production technique are not quite similar, so each control of process parameters is also different.

Big specification 82B high-carbon Wire Rod is meant the wire-rod roll of diameter greater than 12.5mm.

Table 1 and table 2 are respectively the original 82B steel mechanical property of producing of certain iron and steel enterprise and the mechanical property of customer requirements.Can find out that by the contrast of table 1 and table 2 mechanical property of these two specifications compares on the low sidely with customer requirements, MV just reaches user's minimum requirements.Because the technology controlling and process means of wire rod production line are limited, therefore decision is adjusted the composition of big specification 82B steel.

The original SWRH82B mechanical property statistics of table 1 (sample number respectively is 10 stoves)

Table 2 user is to the requirement of big specification SWRH82B wire rod mechanical property

Specification, mm	Tensile strength, MPa	Relative reduction in area, %
			Φ13	≥1200	≥30
Φ15	≥1180	≥28

Summary of the invention

The objective of the invention is on original 82B composition of steel basis,, to improve its mechanical property through suitable interpolation Cr element and V element.

Through the 25kg vacuum induction furnace test in early stage, find out when the composition range of molten steel is as shown in table 3, then can satisfy customer requirements.

The composition and the content of the big specification 82B steel of table 3, w%

Steel grade

C

Si

Mn

Cr+V

Al

P

S

82B

0.79-0.84

0.15-0.35

0.70-0.90

0.1-1.0

≤0.008

≤0.030

Concrete industrial production is following:

1, converter production

The carbon content of converter terminal molten steel, phosphorus content and tapping temperature are following:

Tapping temperature (℃) 1630-1650, average 1638; Carbon content (%) 0.06-0.15, average 0.11; Phosphorus content (%) 0.011-0.020, average 0.16.

2, the LF stove is produced

Refining temperature in place (℃) 1504-1581, average 1519; Refining off normal temperature (℃) 1557-1605, average 1564; Refining treatment time (min) 30-56, average 40.

3, the VD stove is produced

The dark vacuum time that requires the smelting of VD stove is all greater than 15min.

Soft blow time (min) 10-14, average 11; Soft blow flow (Nl/min) 20-99, average 65; Appear on the stage temperature (℃) 1513-1550, average 1518.

4, continuous casting production

Superheating temperature is controlled between 20-32 ℃ in the continuous casting production, and pulling rate is between 0.6m/min-0.75m/min.

5, rolling

After to be that the bloom of 280mm * 380mm is rolling be the square billet of 152mm * 152mm for section with section, deliver to high speed wire rolling.Steel billet the process furnace internal heating time greater than 2 hours, the steel billet start rolling temperature is controlled cold rolling to wire rod in 1130 ℃-1170 ℃ scope, rolling wire gage is Φ 13mm and Φ 15mm.

Embodiment

The commerical test production technique is summarized as follows:

Vacuum outgas-the bloom continuous casting of the ladle furnace refining of converter smelting-(LF)-(VD) (280mm * 380mm)-the beam-and-rail cogging (152mm * 152mm)-high speed wire rolling.

THE INDUSTRIAL TRIAL 20 stove steel, the control of concrete processing parameter as follows:

1) converter production

The carbon content of converter terminal molten steel, phosphorus content and tapping temperature are as shown in table 4.

The composition and the temperature of the big specification 82B steel converter tapping of table 4

	Tapping temperature, ℃	The tapping carbon content, %	The tapping phosphorus content, %
				Minimum value	1631	0.06	0.011
Peak	1647	0.15	0.020
				MV	1638	0.11	0.16

2) the LF stove is produced

The big specification 82B steel refining LF furnace temperature control of table 5

	Refining temperature in place, ℃	The refining temperature of offing normal, ℃	The refining treatment time, min
				Minimum value	1504	1557	?30
Peak	1581	1605	?56
				MV	1519	1564	?40

3) the VD stove is produced

The dark vacuum time that requires the smelting of VD stove is all greater than 15min, and other processing parameter is seen table 6.

Big specification 82B steel refining furnaceman VD of table 6 control of planting

	The soft blow time, min	The soft blow flow, Nl/min	The temperature of appearing on the stage, ℃
				Minimum value	?10	20	1513
Peak	?14	99	1550
				MV	?11	65	1518

4) continuous casting production

Superheating temperature is controlled between 20-32 ℃ in the continuous casting production, and pulling rate is between 0.6m/min-0.75m/min, and the Composition Control of molten steel is as shown in table 7.

The big specification 82B steel finished product composition of table 7

	C	Si	Mn	Cr+V	Al	P	S
								Minimum value	0.79	0.17	0.73	0.33	0.001	0.013	0.008
Peak	0.83	0.34	0.87	0.42	0.007	0.025	0.020
								MV	0.81	0.29	0.82	0.38	0.005	0.021	0.015

4) steel rolling production

Section be the bloom of 280mm * 380mm rolling be to high speed wire rolling for section behind the square billet of 152mm * 152mm.Steel billet the process furnace internal heating time greater than 2 hours, the steel billet start rolling temperature is controlled cold rolling to wire rod in 1130 ℃-1170 ℃ scope.

5) service check

The performance test results of the big specification 82B steel of table 8 (each 10 stove of Φ 13mm and Φ 15mm)

Visible by table 8,20 stove steel mechanical properties of test satisfy requirement of client fully, so the design of steel grades is rational.

Claims

1. the working method of one kind big specification 82B high-carbon Wire Rod is characterized in that the composition of this steel grade and weight percentage are: carbon 0.79-0.84%, silicon 0.15-0.35%; Manganese 0.70-0.90%; Chromium and vanadium sum are greater than 0.1% but less than 1.0%, and aluminium is smaller or equal to 0.008%, and phosphorus is smaller or equal to 0.030%; Sulphur is smaller or equal to 0.030%, and all the other are iron and unavoidable impurities; The tapping temperature 1630-1650 of converter terminal molten steel ℃, carbon content 0.06-0.15%, phosphorus content 0.011-0.020%; The refining of LF stove temperature 1504-1581 in place ℃, refining is offed normal temperature 1557-1605 ℃, refining treatment time 30-56min; The dark vacuum time that the VD stove is smelted is greater than 15min, soft blow time 10-14min, soft blow flow 20-99Nl/min, 1513-1550 ℃ of the temperature of appearing on the stage; Superheating temperature is controlled at 20-32 ℃ in the continuous casting production, and pulling rate is at 0.6m/min-0.75m/min; Rolling heat-up time is greater than 2h; 1130 ℃-1170 ℃ of steel billet start rolling temperatures are controlled cold rolling, and rolling wire gage is respectively Φ 13mm and Φ 15mm; And the tensile strength that makes Φ 13mm wire rod is more than or equal to 1200Mpa; Relative reduction in area is more than or equal to 30%, and the tensile strength of Φ 15mm wire rod is more than or equal to 1180Mpa, and relative reduction in area is more than or equal to 28%.