Title of Invention	"A PROCESS FOR THE MANUFACTURE OF HIGH STRENGTH WELDABLE REINFORCED RIBBED WIRE ROD AND DRAWING QUALITY WIRE ROD"
Abstract	There is provided a process for the manufacture of high strength weldable reinforced ribbed wire rod and drawing quality wire rod comprising: A) melting steel having the following alloying elements viz. a) Carbon - 0.07 to 0.10% b) Manganese-0.30 to 0.50% c) Silicon-0.20% max. d) Sulphur - 0.03% max. e) Phosphorous - 0.04% max. In a twin open hearth furnace, B) tapping the molten steel at temperatures in the range of 1610 ± 10 ° C in a ladle with ferro alloys, which is preheated, C) adding Niobium in the range of 0.008 to 0.015 % to the molten steel in the ladle, D) casting the molten steel into ingots, E) soaking the ingots at 1300 ° ± 10 ° C, F) rolling the ingots into billets, G) re-heating billet and soaking billets at temperatures of around 1250 ± 10 ° C H) rolling the billets at finish rolling temperature of 950 ° to 1000 ° C , I) subjecting the rolled billets to an air cooling operation, J) coiling the rolled wire rods of SWR 10/14 at coiling temperatures of 850 ° to 900 ° C K) with the proviso that a part of the rolled billet is simultaneously subjected to operation in a TMT line and TMT ribbed wire rod is prepared.

Title of Invention

"A PROCESS FOR THE MANUFACTURE OF HIGH STRENGTH WELDABLE REINFORCED RIBBED WIRE ROD AND DRAWING QUALITY WIRE ROD"

Abstract

There is provided a process for the manufacture of high strength weldable reinforced ribbed wire rod and drawing quality wire rod comprising: A) melting steel having the following alloying elements viz. a) Carbon - 0.07 to 0.10% b) Manganese-0.30 to 0.50% c) Silicon-0.20% max. d) Sulphur - 0.03% max. e) Phosphorous - 0.04% max. In a twin open hearth furnace, B) tapping the molten steel at temperatures in the range of 1610 ± 10 ° C in a ladle with ferro alloys, which is preheated, C) adding Niobium in the range of 0.008 to 0.015 % to the molten steel in the ladle, D) casting the molten steel into ingots, E) soaking the ingots at 1300 ° ± 10 ° C, F) rolling the ingots into billets, G) re-heating billet and soaking billets at temperatures of around 1250 ± 10 ° C H) rolling the billets at finish rolling temperature of 950 ° to 1000 ° C , I) subjecting the rolled billets to an air cooling operation, J) coiling the rolled wire rods of SWR 10/14 at coiling temperatures of 850 ° to 900 ° C K) with the proviso that a part of the rolled billet is simultaneously subjected to operation in a TMT line and TMT ribbed wire rod is prepared.

Full Text	This invention relates to a process for the manufacture of high strength weldable reinforced ribbed wire rod and drawing quality wire rod. This invention more particularly relates to a process for simulations manufacture of high strength weldable Fe 415 Gr TMT reinforcement ribbed wire rod (8/10 mm) and drawing quality wire rod (8/10 mm) equipment to SWR 14 / SWR 10 Gr Steel. It is already known to manufacture high strength weldable reinforcement ribbed wire rods, which are used in concrete structure. It is already known Fe 415 Gr TMT wire rod has yield stress 415 Mpa (min) and is used in concrete structures. SWR 14/SWR to Gr are drawing quality plain wire rod used as barbed wire, nails, wire mesh for fencing etc In the prior Art whenever there is production of Fe415 Gr Wire rod through the TMT line, ordinary wire rod with poor drawing characteristics is produced through the conventional air-cooled line. Since both TMT line and air-cooled line are to be operated simultaneously, production of ordinary wire rod causes loss of revenue. OBJECTS OF THE INVENTION: It is a primary object of this invention to propose an improved method for the manufacture of ribbed high strength weldable rods as well as plain rods more economically than so far possible. It is another object of this invention to propose such a method, which can produce both ribbed wire rod and plain wire rod simultaneously. It is a further object of this invention to propose an improved chemistry of steel used for manufacture of high strength weldable reinforcement ribbed wire rod and plain wire rod simultaneously. BACKGROUND OF THE INVESTIGATION: In order to achieve the objects of this invention we have studied the chemistry of steel used so far in the manufacture of ribbed wire rod and plain wire rod. 2 We have found that a chemistry of steel for Fe 415, Gr TMT (Thermo Mechanically Tested) wire rod and ordinary plain wire rod (8 to 10 mm) is as follows: Previous chemistry for Fe 415 Gr TMT wire rod and ordinary plain wire rod (8/10 mm) c 0.18-0.23 Mn 0.9-12 Si 0.10 max S 0.04 max P 0.04 max After a lot of trials, investigations and research, we have now found that the chief alloying ingredients viz Carbon and manganese can be substantially reduced without sacrificing quality of ribbed wire rod and drawing quality plain wire rod provided the amount of phosphorous used in the prior art is increased. It has also been found by us that similar results can be obtained with the reduction in the amounts of carbon and manganese keeping the phosphorous amount as the same in the prior art provided niobium is used as an additional alloying element. Our detailed investigations have revealed that a preferable range of 0.008 to 0.015% of niobium can achieve our objectives with the same amount of phosphorous as used in the known art inspite of substantial reduction in the amounts of carbon and manganese. Similarly it has also been found by us that when niobium is not used, increasing the phosphorous content as alloying element two to three times more than the amount used so far, helps in achieving our objective even after substantial reduction of carbon and manganese. These two above alternatives result in highly economical process. 3 We give below the new chemistry of steel: New Chemistry for Fe 415 Gr TMT wire rod and SWR 10/14 Gr plain rod (8/10 mm) (in %) With P With Nb c 0.07-0.10 0.07-0.10 Mn 0.30 - 0.50 0.30-0.50 Si 0.20 max 0.20 max S 0.03 max 0.03 max P 0.08-0.10 0.04 max Nb 0.008-0.015 4 The process flow chart is shown in fig. 1. The steel was melted in twin OHF and tapped at 1610 ± 10 C in a preheated ladle containing ferro alloys excluding niobium which was added in the molten stream of steel in the ladle. The steel was cast to ingots weighing 9 T each. Ingots were soaked at 1300 ± 10 ° C for 4 hours and roiled to billets of size 100x100 mm. These billets were further reheated at 1250 ° C and rolled to 8/10 dia wire rod through the TMT line and air cooled line. The finish rolling temperature was 950 -1000 °C and the laying head temperature was 650-700 °C for TMT wire rod and 850-900 ° C for air cooled plain wire rod. The typical mechanical properties are given below: TMT wire rod (8 mm) SWR 10 / SWR 14 wire rod (8 mm) YS (Mpa) 493 290 UTS (Mpa) 597 458 El (%) 28.8 37.4 RA (%) 67.3 72.9 The plain wire rods were further drawn to 2.0 mm dia and 2.60 mm dia by batch and continuous process respectively. The invented process has high potential as it enables simultaneous production of TMT Fe 415 Si wire rod and drawing quality SWR 10 / SWR 14 wire rod using leaner chemistry. 5 We Claim: 1 A process for the manufacture of high strength weldable reinforced ribbed wire rod and drawing quality wire rod comprising: A) Melting steel having the following alloying elements viz. a) Carbon - 0.07 to 0.10% b) Manganese - 0 30 to 0.50% c) Silicon - 0.20% max. d) Sulphur - 0.03% max. e) Phosphorous - 0.04% max. in a-twin open hearth furnace, B) tapping the molten steel at temperatures in the range of 1610 ± 10 ° C in a ladle with conventional ferro alloys like ferro- manganese, ferro -silicon and ferro phosphorus, which is preheated, C) adding ferro Niobium in the range of 0.008 to 0.015 % to the molten steel while it is being poured into the ladle, D) casting the molten steel into ingots, E) soaking the ingots at 1300° ±10°C, F) rolling the ingots into billets in the usual manner, G) re-heating billet and soaking billets at temperatures of around 1250 ±10 C H) rolling the billets at finish rolling temperature of 950 ° to 1000 ° C , I) subjecting the rolled billets to an air cooling operation, J) coiling the rolled wire rods of SWR 10/14 at coiling temperatures of 850 ° to 900 ° C, K) With the proviso that a part of the rolled billet is simultaneously subjected to operation in a TMT fine as herein described and TMT ribbed wire rod is prepared 6 2. The method as claimed in Claim-1 wherein the ingot after soaking is subjected to bloom rolling before it is subjected to billet rolling. 3 The method as claimed in Claim-1 wherein the TMT ribbed wire rod is coiled at 650 to 700° C. 7 4. The method as claimed in Claim-1 wherein the air-cooied line is simultaneously operated and the wire rod is coiled at temperatures of 850° to 900° C. 5. A process for the manufacture of high strength weldabte reinforced ribbed wire rod and drawing quality wire rod simultaneously as herein described. There is provided a process for the manufacture of high strength weldable reinforced ribbed wire rod and drawing quality wire rod comprising: A) melting steel having the following alloying elements viz. a) Carbon - 0.07 to 0.10% b) Manganese-0.30 to 0.50% c) Silicon-0.20% max. d) Sulphur - 0.03% max. e) Phosphorous - 0.04% max. In a twin open hearth furnace, B) tapping the molten steel at temperatures in the range of 1610 ± 10 ° C in a ladle with ferro alloys, which is preheated, C) adding Niobium in the range of 0.008 to 0.015 % to the molten steel in the ladle, D) casting the molten steel into ingots, E) soaking the ingots at 1300 ° ± 10 ° C, F) rolling the ingots into billets, G) re-heating billet and soaking billets at temperatures of around 1250 ± 10 ° C H) rolling the billets at finish rolling temperature of 950 ° to 1000 ° C , I) subjecting the rolled billets to an air cooling operation, J) coiling the rolled wire rods of SWR 10/14 at coiling temperatures of 850 ° to 900 ° C K) with the proviso that a part of the rolled billet is simultaneously subjected to operation in a TMT line and TMT ribbed wire rod is prepared.

Full Text

This invention relates to a process for the manufacture of high strength weldable reinforced ribbed wire rod and drawing quality wire rod.
This invention more particularly relates to a process for simulations manufacture of high strength weldable Fe 415 Gr TMT reinforcement ribbed wire rod (8/10 mm) and drawing quality wire rod (8/10 mm) equipment to SWR 14 / SWR 10 Gr Steel.
It is already known to manufacture high strength weldable reinforcement ribbed wire rods, which are used in concrete structure.
It is already known Fe 415 Gr TMT wire rod has yield stress 415 Mpa (min) and is used in concrete structures. SWR 14/SWR to Gr are drawing quality plain wire rod used as barbed wire, nails, wire mesh for fencing etc
In the prior Art whenever there is production of Fe415 Gr Wire rod through the TMT line, ordinary wire rod with poor drawing characteristics is produced through the conventional air-cooled line. Since both TMT line and air-cooled line are to be operated simultaneously, production of ordinary wire rod causes loss of revenue.
OBJECTS OF THE INVENTION:
It is a primary object of this invention to propose an improved method for the manufacture of ribbed high strength weldable rods as well as plain rods more economically than so far possible.
It is another object of this invention to propose such a method, which can produce both ribbed wire rod and plain wire rod simultaneously.
It is a further object of this invention to propose an improved chemistry of steel used for manufacture of high strength weldable reinforcement ribbed wire rod and plain wire rod simultaneously.
BACKGROUND OF THE INVESTIGATION:
In order to achieve the objects of this invention we have studied the chemistry of steel used so far in the manufacture of ribbed wire rod and plain wire rod.
2

We have found that a chemistry of steel for Fe 415, Gr TMT (Thermo Mechanically Tested) wire rod and ordinary plain wire rod (8 to 10 mm) is as follows:

Previous chemistry for Fe 415 Gr TMT wire rod and ordinary plain wire rod (8/10 mm)
c 0.18-0.23
Mn 0.9-12
Si 0.10 max
S 0.04 max
P 0.04 max

After a lot of trials, investigations and research, we have now found that the chief alloying ingredients viz Carbon and manganese can be substantially reduced without sacrificing quality of ribbed wire rod and drawing quality plain wire rod provided the amount of phosphorous used in the prior art is increased.
It has also been found by us that similar results can be obtained with the reduction in the amounts of carbon and manganese keeping the phosphorous amount as the same in the prior art provided niobium is used as an additional alloying element.
Our detailed investigations have revealed that a preferable range of 0.008 to 0.015% of niobium can achieve our objectives with the same amount of phosphorous as used in the known art inspite of substantial reduction in the amounts of carbon and manganese.
Similarly it has also been found by us that when niobium is not used, increasing the phosphorous content as alloying element two to three times more than the amount used so far, helps in achieving our objective even after substantial reduction of carbon and manganese.
These two above alternatives result in highly economical process.
3

We give below the new chemistry of steel:

New Chemistry for Fe 415 Gr TMT wire rod and SWR 10/14 Gr plain rod (8/10 mm) (in %)
With P With Nb
c 0.07-0.10 0.07-0.10
Mn 0.30 - 0.50 0.30-0.50
Si 0.20 max 0.20 max
S 0.03 max 0.03 max
P 0.08-0.10 0.04 max
Nb 0.008-0.015
4

The process flow chart is shown in fig. 1. The steel was melted in twin OHF and tapped at 1610 ± 10 C in a preheated ladle containing ferro alloys excluding niobium which was added in the molten stream of steel in the ladle. The steel was cast to ingots weighing 9 T each. Ingots were soaked at 1300 ± 10 ° C for 4 hours and roiled to billets of size 100x100 mm. These billets were further reheated at 1250 ° C and rolled to 8/10 dia wire rod through the TMT line and air cooled line. The finish rolling temperature was 950 -1000 °C and the laying head temperature was 650-700 °C for TMT wire rod and 850-900 ° C for air cooled plain wire rod.
The typical mechanical properties are given below:

TMT wire rod (8 mm) SWR 10 / SWR 14 wire rod (8 mm)
YS (Mpa) 493 290
UTS (Mpa) 597 458
El (%) 28.8 37.4
RA (%) 67.3 72.9
The plain wire rods were further drawn to 2.0 mm dia and 2.60 mm dia by batch and continuous process respectively.
The invented process has high potential as it enables simultaneous production of TMT Fe 415 Si wire rod and drawing quality SWR 10 / SWR 14 wire rod using leaner chemistry.
5

We Claim:
1 A process for the manufacture of high strength weldable reinforced ribbed wire rod and drawing quality wire rod comprising:
A) Melting steel having the following alloying elements viz.
a) Carbon - 0.07 to 0.10%
b) Manganese - 0 30 to 0.50%
c) Silicon - 0.20% max.
d) Sulphur - 0.03% max.
e) Phosphorous - 0.04% max.
in a-twin open hearth furnace,
B) tapping the molten steel at temperatures in the range of 1610 ± 10 ° C in a ladle with
conventional ferro alloys like ferro- manganese, ferro -silicon and ferro phosphorus,
which is preheated,
C) adding ferro Niobium in the range of 0.008 to 0.015 % to the molten steel while it is being
poured into the ladle,
D) casting the molten steel into ingots,
E) soaking the ingots at 1300° ±10°C,
F) rolling the ingots into billets in the usual manner,
G) re-heating billet and soaking billets at temperatures of around 1250 ±10 C
H) rolling the billets at finish rolling temperature of 950 ° to 1000 ° C ,
I) subjecting the rolled billets to an air cooling operation,
J) coiling the rolled wire rods of SWR 10/14 at coiling temperatures of 850 ° to 900 ° C,
K) With the proviso that a part of the rolled billet is simultaneously subjected to operation in a TMT fine as herein described and TMT ribbed wire rod is prepared

6

2. The method as claimed in Claim-1 wherein the ingot after soaking is subjected to bloom
rolling before it is subjected to billet rolling.
3 The method as claimed in Claim-1 wherein the TMT ribbed wire rod is coiled at 650 to
700° C.
7
4. The method as claimed in Claim-1 wherein the air-cooied line is simultaneously operated
and the wire rod is coiled at temperatures of 850° to 900° C.
5. A process for the manufacture of high strength weldabte reinforced ribbed wire rod and
drawing quality wire rod simultaneously as herein described.
There is provided a process for the manufacture of high strength weldable reinforced ribbed wire rod and drawing quality wire rod comprising:
A) melting steel having the following alloying elements viz.
a) Carbon - 0.07 to 0.10%
b) Manganese-0.30 to 0.50%
c) Silicon-0.20% max.
d) Sulphur - 0.03% max.
e) Phosphorous - 0.04% max.
In a twin open hearth furnace,

B) tapping the molten steel at temperatures in the range of 1610 ± 10 ° C in a ladle with ferro
alloys, which is preheated,
C) adding Niobium in the range of 0.008 to 0.015 % to the molten steel in the ladle,
D) casting the molten steel into ingots,
E) soaking the ingots at 1300 ° ± 10 ° C,
F) rolling the ingots into billets,
G) re-heating billet and soaking billets at temperatures of around 1250 ± 10 ° C
H) rolling the billets at finish rolling temperature of 950 ° to 1000 ° C ,
I) subjecting the rolled billets to an air cooling operation,
J) coiling the rolled wire rods of SWR 10/14 at coiling temperatures of 850 ° to 900 ° C
K) with the proviso that a part of the rolled billet is simultaneously subjected to operation in a TMT line and TMT ribbed wire rod is prepared.

Documents:

00060-kol-2004 abstract.pdf

00060-kol-2004 claims.pdf

00060-kol-2004 correspondence.pdf

00060-kol-2004 description(complete).pdf

00060-kol-2004 drawings.pdf

00060-kol-2004 form-1.pdf

00060-kol-2004 form-13.pdf

00060-kol-2004 form-18.pdf

00060-kol-2004 form-2.pdf

00060-kol-2004 form-3.pdf

00060-kol-2004 form-5.pdf

00060-kol-2004 letters patent.pdf

00060-kol-2004 p.a.pdf

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Patent Number

202619

Indian Patent Application Number

60/KOL/2004

PG Journal Number

09/2007

Publication Date

02-Mar-2007

Grant Date

02-Mar-2007

Date of Filing

16-Feb-2004

Name of Patentee

M/S STEEL AUTHORITY OF INDIA LIMITED

Applicant Address

OF RESEARCH & DEVELOPMENT CENTRE FOR IRON AND STEEL P.O-DORANDA RANCHI 834002

Inventors:

#	Inventor's Name	Inventor's Address
1	PANIGRAHI BIMAL KUMAR	OF RESEARCH & DEVELOPMENT CENTRE FOR IRON AND STEEL P.O-DORANDA RANCHI
2	JAIN SURENDRA KUMAR	RESEARCH & DEVELOPMENT CENTRE FOR IRON AND STEEL P.O-DORANDA RANCHI-834002
3	SINGH RAM BRIKSH	BHILAI STEEL PLANT FOR IRON AND STEEL BHILAI -490001

PCT International Classification Number

C 22 C 38/02

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA