Ferro Alloys for Micro-alloying of Steel

MICROALLOYED STEELS:

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Microalloyed (MA) steels have matured during the past 40 years into an important class of high-strength structural materials. Their cost-effectiveness has been enhanced by the growth of electric-arc-fumace (EAF) steelmaking and the thin-slab-casting process.

Microalloying is a term that is used to describe the deliberate addition of very small amounts of elements, usually individually below 0.1wt% to improve the steel properties. This is different from trace elements, which are usually undesirable. The development of microalloyed steels eliminated the need for heat treatments, such as normalizing. Yield strengths ranging up to 550 to 600 MPa can be attained through small additions (less than 0.1%) of selected carbonitride formers without requiring costly alloying elements. Recent technological developments in steel melting and hot rolling further reduced the cost and enhanced the competitiveness of microalloyed steels.

In such steels Niobium, Vanadium and Titanium are added either singularly or in combination. Since the solubility product and the physical properties of each element and each compound are different, there exist characteristic differences which cause each of these elements to have specific merits. Sometimes boron is also added in smaller quantity (0.00596 /0.00396) for improving the steel properties.

The effects of various additives are given below:

Titanium forms nitrides, which are stable at high temperatures and these titanium nitrides provide control of the austenite grain size at the reheating temperature before hot working and also in the weldment, in particular in the heat affected zone close to the fusion boundary. The elimination of free nitrogen due to the formation of TiN is positive for the toughness and indirectly makes niobium more effective.

Vanadium forms almost no austenite precipitates and is plentifully available for precipitation hardening. Even though the specific efficiency of vanadium compounds is comparably low, the high volume fraction of fine precipitates compensates for this, especially in steels with relatively high carbon content.

Niobium is the most effective microalloy for grain refinement by controlling the austenite grain size during the reheating processes for heat treatments like normalizing, quenching or carburi,ng, acting additionally to the traditional AIN technology. Furthermore it has an outstanding status in retarding recrystallisation during austenite processing via thermomechanical rolling, resulting in grain refinement, which cannot be obtained by any heat treatment process.

Ti, V and Nb can be added in to liquid steel in the form of Ferro alloys either lumps or cored wire. Use of cored wire results in higher recovery of additions. Ferroalloys (lumps and cored wires) manufactured by MINEX for microalloying of steels has following specifications and can also be tailor made as per the specific requirement of customers.

Ferro Titanium:

Alloy Grade Chemical
Composition (%)
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Ti Si AI
(Max)
c
(Max)
s
(Max)
p
(Max)
N
(Max)
0
(Max)
v
(Max)
Sn
(Max)
Fe
FeTi 25-30 25-30 3 4 0.15 0.050 0.050 0.01 0.2 3.5 0.50 Bal
FeTi 30 SPl 28-32 2 5 0.15 0.050 0.050 0.03 0.03 2.0 0.50 Bal
FeTi 30-35 30-35 3 4 0.15 0.050 0.050 0.01 0.2 3.5 0.50 Bal
FeTi 60-65 60-65 3 5 0.10 0.050 0.050 0.60 1.8 3.5 0.50 Bal
FeTi 65-70 65-70 3 5 0.10 0.050 0.050 0.60 1.8 3.5 0.50 Bal
FeTi 70 SPl 68-72 2 5 0.10 0.050 0.050 0.03 0.03 2.0 0.50 Bal
FeTi 1-1' 2.5 68-72 0.25 2.5 0.10 0.050 0.050 0.03 0.03 1.75 0.50 Bal
FeTi 1-1' 1 68-72 0.25 1.0 0.10 0.050 0.050 0.03 0.03 0.75 0.20 Bal
FeTi 1-1' 0.5 68-72 0.25 0.5 0.10 0.050 0.050 0.03 0.03 0.25 0.20 Bal
Physical Properties
Grade Specific Gravity (gm/CC) Melting Range (0C) Chill Factor (0C) Reference Standard
IS 1468 1989/1990
ISO 7692: 1983
FeTi 25-­30 6.4 1350-­1500 -­16.4±4
FeTi 30-­35 5.9 1335-­1480 -­16.3±4
FeTi 60-­65 5.5 1080-­1160 -­12.6±4
FeTi 65-­70 5.4 1070-­1135 -­12.3±4

*Chill factors are the temperature changes in 0C of a steel bath at 1600 0C
after a 1 wt. % addition of Ferro-­alloys & metals at room temperature.

Shape & Size

  Std. Size (mm)
Lumps 10, 25, 50, 80, 100, 150
Granules 10, 5, 2 cartier replica watches
Powder 1-2, 0.30-1.50,0.10-1, 18, Below 1mm & Below 36 and 60 Mesh.
Cored Wire See the Cored wire specification section.

 

FeTi Cored Wire Specification:

 

Grade Powder Chemical Composition (%)
Ti Si
(Max)
Al
(Max)
C
(Max)
V
(Max)
O N Fe
FeTi 70 65-70 2 5 0.10 2 0.03 0.03 Bal.

 

Powder specification
Grade density (g/cm3) Melting Point (°C) Size (mm)
FeTi 70 5.4 1070-­1135 -­1.4+0.212
Strip Specification
Grade Diameter
(0, mm)
Thickness (mm)
EDD IS – 513

9±0.5

13±0.2

0.40±0.03

0.40± 0.03

Wire Characteristics
Grade Diameter ( 0, mm) Shape Powder Fill (gm/mt)

FeTi 70

 

9±0.5

13±0.2

Round

Round

190±10

370 ± 10

Coil Specification (Flipping Coil – Horizontal & Vertical)
Details 9 mm 0

13 mm 0

Coil Identification

 

F1-02 F1-05 F2-05 F2-10
Powder Weight
(MT)
0.250 0.500 0.500 1.0

All coils are color coded and fixed with a detailed sticker clearly displaying details such as coil no., powder content, strip weight, gross weight density & length. A fluorescent sticker displays the name of the product in bold letters on the outer diameter of the coil.

Handling

No metal sling, chain or rod is to be used across the ID of the coil for handling as it may damage the coil. Use only polyester, synthetic slings, fork lift/tractor to handle the coil. The pallet is an integral part of the coil and it is to be removed till the coil is consumed.

Shelf Life

Follow the shelf life period specified by MINEX








Strip Weight
(MT)
0.128 0.320 0.225 0.450
Net Weight
(MT)
0.387 0.775 0.700 1.400
Length (Mtrs) 1315 2631 1351 2702
Internal
Diameter (mm)
650 650 650 650
External
Diameter (mm)
700 750 950 1050
Height (mm) 630 630 630 630
Packing Storage & Safety

Packed in flipping cage and mounted on wooden / mild steel pallet and Strapped with pallet horizontally or vertically. All coils are wrapped in stretch film & palletized.

To be stored in dry & covered area away from heat and moisture. Material Safety data sheet can be Supplied on demand.

Ferro Vanadium:

FeV Alloy Composition:

 

Alloy Powder Chemical Composition (%)
Grade V C (Max) Si (Max) S (Max) P (Max) Al
(Max)
Fe
FeV 60 50-60 0.30 1.50 0.05 0.10 2 Bal

 

Physical Properties
Grade Sp. Gravity (gm/CC) Melting Range (0C) Chill Factor (0C)
FeV 60 6.8-­6.9 1555-­1600 -­18.1±5

 *Chill factors are the temperature changes in 0C of a steel bath at 1600 0C after a 1 wt. % addition of Ferro-­alloys & metals at room temperature.

Shape & Size

  Std. Size (mm)
Lumps 10-40, 10-80
Powder 1-2, 0.30-1.50 & Below 0.50
Granules 2-4, 2-5

Packing

Steel Drum
*200/250 Kg*
#100/150 Kg#
*Standard Packing, #Optional Packing

Storage

Use Dry & Cool Place to store the material

Ferro Vanadium Cored Wire can be supplied, as per customer’s requirement.

FeNb Alloy Composition:

Alloy Powder Chemical Composition (%)
Grade Nb C (Max) Si
S (Max) P (Max) Ti Al
(Max)
Fe
FeNb 60-70 60-70 0.20 2.5-4 0.05 0.20 0.4-2.5 1-6 Bal
FeNb 65-70 65-70 0.1 1 0.05 0.05 - 1 Bal

 

Physical Properties
Grade Sp. Gravity (gm/CC) Melting Range (0C) Chill Factor (0C)
FeNb 60-­70 8.1-­8.3 1510-­1540 -­10.7±2.0

 *Chill factors are the temperature changes in 0C of a steel bath at 1600 0C after a 1 wt. % addition of Ferro-­alloys & metals at room temperature.

Shape & Size

  Std. Size (mm)
Lumps 10-80
Granules 2-5, 0.40-4.0
Powder 1-2, 0.30-1.50, & Below 1
Granules 2-4, 2-5

Packing

Steel Drum
*50/100 Kg*
#250/400 Kg#

*Standard Packing, #Optional Packing

Storage

Use Dry & Cool Place to store the material Steel Drum

Safety

Material Safety Data Sheet can be supplied on demand

Ferro Vanadium Cored Wire can be supplied, as per customer’s requirement.

 

Grade Powder Chemical Composition (%)
Nb Al (Max) Si
(Max)
C
(Max)
S
(Max)
P (Max) Fe (Max)
FeNb 65-70 65-70 1 1 0.1 0.05 0.05 Bal.

 

Powder specification
Grade Density (gm/CC) Melting
Point
(°C)
Size (mm)
FeNb 65-­70 8.3-­8.4 1510-­1540 -­2.0+0.212
Strip Specification
Grade Diameter
(0, mm)
Thickness (mm)
EDD IS-­513 9± 0.5 0.40± 0.03
Wire Characteristics
Grade Diameter ( 0, mm) Shape Powder Fill (gm/mt)
FeNb 9± 0.5 Round 260 ± 10
Coil Specification (Flipping Coil – Horizontal & Vertical)
Details

13 mm 0

Coil Identification

F1-05

Powder Weight
(MT)
0.250

All coils are color coded and fixed with a detailed sticker clearly displaying details such as coil no., powder content, strip weight, gross weight density & length. A fluorescent sticker displays the name of the product in bold letters on the outer diameter of the coil.

Handling

No metal sling, chain or rod is to be used across the ID of the coil for handling as it may damage the coil. Use only polyester, synthetic slings, fork lift/tractor to handle the coil. The pallet is an integral part of the coil and it is to be removed till the coil is consumed.

Shelf Life

Follow the shelf life period specified by MINEX








Strip Weight
(MT)
0.070
Net Weight
(MT)
0.320
Length (Mtrs) 961
Internal
Diameter (mm)
650
External
Diameter (mm)
725
Height (mm) 630
Packing Storage & Safety

Packed in flipping cage and mounted on wooden / mild steel pallet and Strapped with pallet horizontally or vertically. All coils are wrapped in stretch film & palletized.

To be stored in dry & covered area away from heat and moisture. Material Safety data sheet can be Supplied on demand.