Evotech Pvt. Ltd., Sister Concern of Evcon Technologies, Providers of Evcon Turbo TMT System
Wire Rod Mill
Consultancy for Conventional and No-Twist Block High Speed Mills
1. Design
  • Layout & Designing of the new mill
  • Detailed drawing of the equipments.
  • Rolling schemes as per requirements.
  • Design of rolling tackles
2. Rolling
Different Grades
  • Mild steel
  • Rimming steel and low carbon for electrodes
  • High carbon and alloy steel, Ball bearing
  • Stainless steel
Different Sections
  • Tor Steel and TMT bars 8mm to 32mm in straight length
  • Tor /TMT( 8 to12 mm in coils if required)
  • Plain sections 5.5 to 16 mm in coil form
  • Higher sections in straight line on the cooling bed.
3. Revamping - Reprofitting
  • Of obsolete and unviable units
  • Rolling lines
  • Product finishing areas.
4. Upgradation
  • Enhancing the capacity of the units
  • Introduction of higher input size
  • Incorporation of the rolling of low profiles 5.5, 6.0 mm
  • Uniform Rolling scheme for different sections
5. Commission and Stabilizing
  • Erection and Commissioning of the units
  • Trials & Stabilization of the units
  • Commercial production
6. Imporvement of Techno-Economic Parameters
  • Improvement in yield and Mill utilization
  • Improvement in power & fuel consumption
  • Improvement in down time of the mill
7. Devalopment of New Products
  • New section/ Profiles as per market demand
  • Developments of rolling tackles
  • Developments of new rolling parameters
8. Block Mill High Speed Rolling
  • Erection & commissioning
  • Setting of block units
  • Shears, pinch rolls and laying head/coiler
  • Pre Primary and secondary cooing lines
  • Stelmore cooling process
  • Reforming tub, Coil collector mandrel, coil off loader device
9. Automation
  • Of the mill parameters
  • Control of the rolling process, loopers
  • Control of the cooling parameters
  • Other process parameters
10. Training and Development

Cooling Bed
Equipments before Cooling Bed
  • Pinch roll
  • Flying shear
  • Tail breaking unit
Automatic Cooling Bed with following facilities
  • Twin channel for receiving the processed bars
  • Auto transfer of bars
  • Aligning of bars
  • Transfer mechanism
  • Run out roller table
  • Shear and bundling mechanism
Approach towards Modern Wire Rod Mills
Approach towards Modern Wire Rod Mills Classfication
Finished products (rounds) are classified into three major categories to have broader understanding of the product range :
  1. Rods Dia 10mm and above
  2. Wire rod Dia between 5mm to 10 mm
  3. Wires Dia 5 mm and below
Out of these wire rod product is the key product with multiple use in wire drawing industries to reduce the size to 0.2mm to 4mm based on the requirements.

Secondly 8 & 10 mm in the form of Rebar and TMT are basically required for the building construction.

Quality of Wire Rods
  • Close dimensional tolerances of the end product +- 0.10mm and ovality 0.2mm
  • Scale loss 0.5 to 0.6 %
  • Negative tolerances (In sectional weight)
  • No variation in dimensions throughout the length of the bar
  • Uniform physical properties
  • Uniform weight with nominal variation between middle and back end
No Twist Block Technology
No Twist Block Technology No twist Block technology with primary and controlled cooling is the solution to the above requirements. The conventional Cast Iron rolls with usual pass life of 50-70 T are replaced by Tungston Carbide Rings having pass life of 600 to 700 T with super finished surface of the end product.

Uniform properties and scale loss upto 0.6% is achievable as all the turns are subjected to the process treatment separately.

Advantages
  • Rolling in coil form from 5.5mm to 12mm
  • Rolling at Higher speed of the order of 50 to 100 mtrs/sec
  • Reduced maintenance and higher mill availability
  • Reduced stand changing /pass changing
  • All quality of steel can be rolled (low carbon, Medium carbon & high carbon)
  • Quality product as per the specific requirements
Conventional
  • Roll changing time is higher
  • Setting needs more time
  • Spring action upsets the sectional tolerances
  • Optical alignment needs more time
  • On spot setting is essential
  • Section control is difficult
  • Maintenance frequency is more
  • Setting after every 50 to 100 Tof steel rolled
  • Frequent stand changing is essential
  • Final speed is restricted to 30m/sec
Block For Finishing Stands
  • Ring changing time is low
  • No setting the Block in position
  • Negligible Spring action
  • On spot setting not required
  • Section control is simpler
  • Maintenance frequency is less
  • Final speed can go upto 80m/sec
  • Rolling in one setting 500-1000T
Selection of Rolls for Finishing Group
Life of one pass is restricted to 50 to 100T Mill down time increases due to the following reasons.
  • Non uniform hardness throughout the depth of the roll
  • Needs frequent changing of the passes
  • Interruption in production
  • Rejection of the trial metal
  • Higher time for roll changing effects production
  • Higher scale loss corresponds to the 2 to 2.5 percentage of the finished material
Tunguston Carbide Ring ( Material- Tungsten carbide ,Co& Ni)
Tunguston Carbide Ring
  • Hardness varies 76 to 85 BHN
  • Uniform properties throughout the depth
  • Life of finishing and pre-finishing pass is
  • 500 to 700T for smaller sections
  • Smooth surface finish
  • Uniform dimensions
  • Needs lesser space
Primary and Controlled Cooling
Primary and Controlled Cooling The practice followed in the modern wire rod units is highly encouraging Control of laying temperature followed by controlled cooling on the conveyor to ensure the properties of the end product to the specific requirements followed by surface finish and minimum secondary scale loss of 0.5-0.6% against 2.5 to 3.0% in conventional and secondary rerollers.

Different process of cooling are put to practice for retarded and accelerated cooling to make the material suitable for wire drawing, TMT, electrode quality and for high Carbon and alloy steel.

Concept of Branding
Each production unit has different technology in some of the key processes. To ensure that the quality product of the reputed concern is available in the market. This is being incorporated for TMT products.
  • To identify the product from concern
  • To distinguish the product from different concerns.
  • Final product in accordance with ISO certification.
  • Customer's satisfaction
Advantages of Contineous Mill
In the competitive scenario of Cost control, quality product, negative tolerances, and rolling at higher speed of the order of 50 to 100 meters per seconds, small units have to adopt the new technology for the survival in the near future. With globalization, and to have competitive, NO-twist block technology is essential in the long run on account of productivity.
  • Setting is easier
  • Human error is eliminated
  • On line control of section is possible
  • Yield is higher to the tone of 96%
  • Mill down time is reduced
  • Frequency of stand /pass changing is reduced
Primary and Controlled Cooling Lines for Wire Rod and Bar Mills
Product Colling in Rod Mills
On the basis of latest development and many years of experience of steel bar and rod mills, leading manufacturers of cooling equipment for long product mills, has focused on cooling systems used in a cost efficient in-line approach which entail energy savings in downstream processes, optimal product structure, and specific physical properties in rolled product for an extremely broad range of applications.
Different Processes followed:
  • Ordinary water-air cooling
  • Enhanced water-cooling to produce reinforcing-grade steel.
  • Enhanced air-cooling to obtain specific product structure.
  • Retarded cooling, e.g. for low-carbon steels.
  • Low-temperature rolling and thermo mechanical treatment through intermediate cooling upstream and within the rod mill block, as well as further water cooling trains ahead of finish rolling.
  • Extremely retarded pot cooling.
Steel Grades
  • Medium and high carbon steel
  • Stainless steel
  • Alloy steel like (en19, en24, etc)
  • Rimming steel / electrode quality
  • Cold headed quality (chq) boron steels
  • Reinforcement bars tmt
  • High corrosion resistance ( hcr)
Cooling facilities offer a number of advantages:
  • Less costly process since thermal after treatment is not required
  • Less mill scale is developed
  • Mill scale removal is easier
  • Additional proceeds are achieved through guaranteed product properties
  • The thermal load to which the mill train and finishing equipment are exposed is reduced.
Technical Information for Cooling Trains
Advantages of EvoTech TechnologyApplication of product cooling is for the controlled temperature reduction in all grades of steel rods in water-cooling trains.

Cooling Train
  • Built as modules suitable for all kinds of local conditions.
  • Core items trains are cooling pipes with strippers.
  • Equipped with high-pressure water systems.
  • Quick-acting gate valves to shut off pressurized water supply to cooling pipes and stripper nozzles during intervals between successive product bars, and admit the coolant again as soon as the leading rod end has passed through.
  • Characterized by a long useful life. All water-bearing components are minimum-corrosion steel.
  • Components through which rolled product passes are of wear resistant material.
  • Cooling pipes are designed such that pressurized water passes through the pipes are available in two basic configurations.
Turbulence cooling pipes serve to ensure high-intensity cooling.. The coolant is optimally utilized, and the product is extremely uniformly cooled along its circumference and length. Separate cooling of pipes is included to rule out excessive heating of a cooling pipe during temporary intervals of "dry" operation.

Special Cooling Tube


Water/Air cooling pipes are used to cool small-diameter rods. Air is metered into the cooling water to yield a homogeneous mixture.

Stripper nozzles are installed downstream of the cooling pipes to remove cooling water or the water/air mixture. jet water is admitted in the opposite direction of traveling rod.

Cooling Process
  • The process is adapted to ensure low-cost production of 6-12 mm dia. TMT (reinforcing grade) product to IS:1786 in any rod mill.
  • Delivered from the rod mill block at a temperature from 950 - 1050oC, the product is cooled in the turbulence cooling train at a fast rate.
  • In this cooling process, a martenstic layer develops on the product edge, and its temper is drawn in downstream temperature- equalizing sections by the heat still present in the core
  • Higher sections 14 and 16 mm TMT can also be incorporated by special arrangements of coiling
  • To improve surface finish.
  • To minimize scale loss.
  • To improve the mill availability of the wire drawing units.
Controlled Cooling
The Controlled Cooling process is advantageous for the user in that:
  • Capital expense is low.
    Yield point (N/mm2) 415 500 550
    Tensile strength N/mm2 485 560 585
    Percent elongation (%) 14.5 12 8
  • Extremely high strength levels are achieved in ribbed product
  • Substantial cost savings are obtained as, by conventional methods, the high rod strength can be achieved only by means of expensive micro alloying elements such as vanadium or-niobium.
  • Little abrasion is experienced in view of the high surface hardness. when the product is uncoiled and straightened for field use.
  • As the maximum carbon equivalent is reduced the product is better suited for resistance, electric and MAG spot welding.
Specified Parameters
Primary Cooling
    Temperature of Bar
  • Block Outlet Temp ( Last Working Stand) = 950-1050oC
  • At Laying Head/Coiler
  • For plain profiles:- =800oC to 850oC
  • For TMT Bars =580oC to 620oC
  • Inlet Cooling water temp:- 34oC
Controlled Cooling Line
  • Forced air-cooling for fast cooling of medium and high carbon steels to achieve microstructure, suitable for direct drawing.
  • Normal cooling of wire rod by switching off the forced air-cooling
  • Slow cooling of wire rod for CHQ steel grades, free cutting steel grades by switching off forced air cooling and covering with insulating covers.
Advantages of EvoTech Technology
Evo-Tech provides No. of below listed advantages in the new units and the existing units rolling different profiles for ( TMT ):
  • The process provided by Evcon is reliable
  • Guaranteed Physical properties.
  • Economical
  • Low maintenance cost
  • Designed for the Indian environmental conditions
  • Secondary scale to the tune of 0.6 to 1.0%
  • Improves the efficiency of the drawing units
Bar Handling cum Bundling Device
Advantages Packaging of the material for all type of products is essential because of the following reasons:
  • Easy handling of the material
  • To keep the Material in tact
  • To ensure good house keeping
  • Creates a healthy atmosphere for working in the shop
  • For reduction of scrap at production shop and at customer's site
  • Maximum utilization of the available space
  • Bundling as per requirements in multiples of Metric Tonnage
  • Easy transportation of the material by rail or by road
  • To avoid pilferage during transportation
  • To control of the damage of the material due to climatic condition.
  • Customers receive the material in good condition
Bundling Unit from EvoTech
Bundling Unit from EvoTech
Systems available for Binding
Wire Binding
Long product in straight length are collected in cradle to form a package of specified tonnage and are further bound manually/ mechanized means at three to four places. Wire-rod of 5 to 6 mm which is being widely used for all such purposes

Strap Binding
Binding material is strap of various thickness and binding operations are semi automatic. The material is collected in cradle and bound by automatic pneumatically operated strapping tools. The strap is tightened around the product fully, sealed and cut by the tool. The system has vantage over wire binding because of the following reasons.
  • Only three strapping are required in place of 4 with binding wire
  • Compactness is better
  • Sustains still higher multiple handlings