Structural steels in Steel plant

Structural steel is a standard construction material made from specific steel grades and is available in industry standard cross sectional shapes. This steel exhibits desirable physical properties such as strength, uniformity of properties, light weight and ease of use etc.
Major applications for these steels are in high rise and tall multi-storey buildings, industrial buildings, towers, tunnels, bridges, road barriers and industrial structures etc.

The common shapes in which structural steels are available consist of sections (beams, channels, Tees section and angles), squares and rounds, hexagons, plates, pipes, hollow square sections, steel cable, Z sections and cold formed sections etc. 

Structural steels for use at ambient or moderately elevated temperatures are of the following types.
1. Carbon and carbon-manganese steels – In these steels the maximum content for alloying elements does not exceed the following: (i) manganese – 1.65 %, silicon – 0.40 % and (iii) copper – 0.6 %. The specified minimum of copper does not exceed 0.4 % and also there is no minimum content is specified for other elements to obtain a desired alloying effect.
2. High strength low alloy (HSLA) steel
3. Heat treated high tensile steels 
4. Constructional alloy steels
5.High performance steels – These steels are with enhanced notch toughness and generally used in construction of bridges. 

Fujian Putian Geili Machinery manufacturing Co., Ltd was founded in 2006, the registered capital of 20,000,000 yuan. The company is located in one of the city center onn the west side of the Straits Economic Zone, Xianyou Putian.

As We are not only a manufacturer of steel machinery, but we have our own steel mill, which can produce deformed bar, angle bar, round steel, wire rod, steel coil, steel plate etc. If you have inquiry in these area, pls don't hesitate to contact us.

Steel profile H Channel

Fuel gases used in steel plant

Fuel gas is a fuel which under ordinary conditions is in the form of gas. Fuel gases are used in steel plants for different applications which include a source of heat as a reductant and cutting and welding application. Fuel gases usually used in steel industry are natural gas (NG), liquefied petroleum gas (LPG), acetylene, by product gases (blast furnace gas, coke oven gas and converter gas).

Natural gas
Natural gas is a gaseous fossil fuel which is extracted from deposits in the earth. It is a mixture of hydro carbons consisting primarily of methane (generally greater than 80 %) but includes varying amounts of other higher alkanes such as ethane, propane and butane etc. 
The main usage of natural gas in the steel industry is in iron making. For production of direct reduced iron it is reformed to produce reducing gases which are then used for the reduction of iron ore. 
In case of iron making in blast furnace, natural gas is being injected in some of the blast furnaces at the tuyeres to reduce the consumption of BF coke and to increase blast furnace productivity. In blast furnace, natural gas plays a double role of a reductant and a fuel.

Liquefied petroleum gas
Liquefied petroleum gas (LPG) is extracted from crude oil. The main components of LPG are hydro carbons containing 3 or 4 carbon atoms. 
LPG is a gas at atmospheric pressure and ambient temperature, but it can be liquefied when moderate pressure is applied or when the temperature is sufficiently reduced. It can be easily condensed, packaged, stored and utilized, which makes it an ideal energy source for a wide range of applications. 
In steel plants, LPG is stored in pressure vessels. 

Blast furnace gas
Blast furnace (BF) gas is a gaseous by product which is generated while producing hot metal (liquid iron) in a blast furnace. 
In steel plants, BF gas is normally being used mixed with either coke oven gas or converter gas or both. The mixed gas is used as a fuel in various furnaces of the steel plant.

Converter gas
During the process of steel making in basic oxygen furnace (BOF), converter gas is generated at a rate around 75 to 95 Cum /ton of crude steel. 

As a professional and experience manufacturer in China, We can give turn-key service from foundation excavation, rolling line design, equipment manufacturing, installation and debugging, technician training depending on prominent capacity of designing and manufacturing and abundant practical experience of installation.

 Continuous casting machine

Steel casting

Steel casting is a specialized form of casting involving various types of steels. Steel castings are used when cast irons cannot deliver enough strength or shock resistance. A steel casting is the product formed by pouring liquid steel into a mould cavity. The liquid steel cools and solidifies in the mould cavity and is then removed for cleaning. Heat treatment may be needed to meet desired properties. This process provides the near net shape and mechanical properties required for meeting the specifications.

The making of a steel casting is a long and complex process. A large investment in capital equipment is required for the melting of steel, manufacturing of cores and moulds and the cleaning and heat treating of castings. Additional major investments for support equipment and facilities are required for sand reclamation systems, dust collection devices and bulk material handling systems etc.

Steel castings are used for vitally important components in the mining, railways, automotive, construction, military, and various industries including oil and gas industries. Steel castings are specified for applications which require weldability, abrasion resistance, high strength, low and high temperature service and corrosion resistance. Though there are large numbers of steel foundries, yet due to the diversity of market requirements such as size, tolerances, chemistry, volume, etc., a single foundry cannot serve all of the market and each foundry tends to specialize in a portion of the total market. Some of the specialized areas are (i) railways, construction equipment, and truck and mining industries, and (ii) high alloy stainless steel used in corrosion and heat resistant applications or low volume prototype and service parts. Examples of items which are produced in the form of steel castings include (i) hydroelectric turbine wheels, forging presses, gears, railway wagon frames, valve bodies, pump casings, mining machinery, marine equipments, turbocharger turbines, and engine cylinder blocks etc.

Continuous casting machine

Reheating furnaces in steel Industry

In steel plants reheating furnaces are used in hot rolling mills to heat the steel stock (Billets, blooms or slabs) to temperatures of around 1200 deg C which is suitable for plastic deformation of steel and hence for rolling in the mill. 

Different type of batch and continuous furnaces are described below.
1.Batch furnace -These are the older type of furnaces which are capable of heating all grades and sizes of steel. 
2.Continuous pusher furnace– In this type of furnace cold steel stock is pushed forward with the help of pushers at the charging side. 
3.Rotary hearth furnace – A rotary hearth furnace is used for heating round billets in pipe plants and for heating short length blooms or billets in a forging plant.
4.Walking beam furnaces – Initially walking beam furnaces were designed with alloy steel walking beams which were exposed directly to the furnace heat and were also subjected to heat corrosion. 
5.Walking hearth furnaces – It is similar to the walking beam furnace when passage of steel stockl through the heating chamber is considered.
6.Roller hearth reheating furnaces – Roller hearth furnaces are used to advantage when heating very long billet, bloom or slabs in the situation where it is not practical for heating in a pusher or walking beam furnace.

Today we are talking about is continuous pusher furnace,Advantages of the pusher type furnaces are as follows:

• High production per unit capital investments

• High hearth area efficiency

• Higher specific production per unit of space utilized.

• Low maintenance cost

• Ease of charging and discharging of material

• Lower temperature differences between two pieces of material pushed.

• More control of the rate of heating at all temperature levels.

• Gradual rise in temperature permits charging of all grades of cold materials.

• Can be built for larger length of the piece to be heated to have higher rolling mill yield

Re-heating furnace

As a professional and experience manufacturer in China, We can give turn-key service from foundation excavation, rolling line design, equipment manufacturing, installation and debugging, technician training depending on prominent capacity of designing and manufacturing and abundant practical experience of installation.

Factors influencing rolling mechanics

Rolling is the most extensively used steel metal forming process, It provides high production and close control of the final product.

Rolling mill for steel

The main factors which influence the mechanics of rolling are as follows.

The diameter of the rollsAmount of reduction in one passThe initial thickness of the material to be rolledThe speed of rolling which decides the strain rateThe front and back tensionsThe nature of friction between the rolls and the steel being rolledThe temperature range of the steel material and the rollsThe physical properties of the steel material being rolledThe shape of the roll contour of roll pass in which the steel material being deformedThe mill behaviour under loadThe effect of previous treatment of the material resulting in work hardening or other effectsThe elastic deformation of rolls under loadThe deformation resistance of the metal as influenced by metallurgy, temperature and strain rate.The state of anisotropy of the materialThe aspect ratio, or the ratio of the width of the rolling stock to the initial thickness


The above parameters may singly or jointly, in combinations of two or more, generate secondary parameters and phenomena more directly related to and commonly associated with the rolling process. Roll pressure, torque, work and power are influenced by these factors. Major of these parameters are given below.

Coefficient of draught, absolute draught and relative draught, which are established by the initial draught, which are established by the initial and final mean thicknesses of the rolling stock.Slip which is characterized by the difference of the linear speed of the rolling stock and the peripheral speed of the rolls. Neutral angle is determined by the point of no slip.

Spread is the difference in width of the exit material as compared to the ingoing rolling stock.

Coefficient of elongation is dependent on the relative values of the draught and spread.

Roll bite which is a function of draught, roll diameter, coefficient of friction and ingoing thickness.

Introduction to Rolling steel -Part 2

A continuous rolling mill has a series of rolling mill stands arranged in succession so as to increase productivity. The steel stock moves at different velocities at each stand in the mill.

In a broader sense, a rolling mill is an automatic system or line of roll stands along with a series of equipments that performs both rolling and auxiliary operations: transport of the original billet/bloom/slab from the stock to the heating furnaces and the mill rolls, transfer of the rolled material from one roll stand to another, turning or twisting in case of some mills, transport of the metal after rolling, cutting, cooling the rolled material on cooling bed in some mills, marking or stamping, trimming, packing, and conveyance to the stock of finished product. In some mills (e.g. hot strip mill, wire rod mill, merchant mill, and cold rolling mill), the rolled product is coiled in a coiler or a wind up reel.

There are different types of rolling mills. These are given below.
1. Continuous rolling mill
2. Reversing rolling mill
3. Transverse rolling mill – Uses circular wedge rolls. The heated bar is cropped to length and fed in transversely between rolls. Rolls revolve in one direction in the mill.
4. Shaped rolling or section rolling mill – Shaped rolling mills are bar mill, merchant mill, wire rod mill, structural mill, beam mill, and rail mill.
5. Powder rolling mill – Metal powder is introduced between the rolls and compacted into a ‘green strip’, which is subsequently sintered and subjected to further hot-working and/or cold working and annealing cycles.
6. Thin slab casting and rolling mill – This is used for the production of hot strips. Liquid steel is cast in thin slabs (thickness 50 mm to 80 mm) which are rolled in finishing mill of hot strip mill after temperature equalization in a furnace.

The above parameters may singly or jointly, in combinations of two or more, generate secondary parameters and phenomena more directly related to and commonly associated with the rolling process. Roll pressure, torque, work and power are influenced by these 
factors.

As a professional and experience manufacturer in China, We can give turn-key service from foundation excavation, rolling line design, equipment manufacturing, installation and debugging, technician training depending on prominent capacity of designing and manufacturing and abundant practical experience of installation.

Steel Rolling Production Line (turnkey service)

Main equipments of Continuous Casting Machine

Continuous casting, also called strand casting, is the process whereby molten metal is solidified into a "semifinished" billet, bloom, or slab for subsequent rolling in the finishing mills. Liquid steel is usually cast in continuous casting machines in the shape of billets, blooms, or slabs. In some plants, it is also being cast in continuous casting machines in the shape of thin slabs or dog bone sections. 

Continuous casting machine is mainly composed of pouring equipment, continuous casting machine ontology, cutting device, dummy bar collection and transportation equipments. the components are as below:

Components:

• Turret charter
• Tundish
• Overflow tank
• Console frame of revolving operation box
• Tundish car
• Mould
• Recooling sprayer device
• Section guide
• Straighten machine
• Vibration device
• Dummy bar
• The storage device of dummy bar
• Pre-cutting roller table
• 45 degree hydraulic shear
• After-cutting roller table
• Cooling bed
• Water cooling system
• Electronic control
• Flying shear

Fujian Putian Geili Machinery manufacturing Co., Ltd was founded in 2006, the registered capital of 20,000,000 yuan. The company is located in one of the city center onn the west side of the Straits Economic Zone, Xianyou Putian. As a professional and experience manufacturer in China, we can supply designing, manufacturing, installation and commissioning of the equipment with "turn-key" service.

Continuous casting machine

Introduction to Rolling steel -Part 1

Liquid steel is usually cast in continuous casting machines in the shape of billets, blooms, or slabs. In some plants, it is also being cast in continuous casting machines in the shape of thin slabs or dog bone sections. These shapes are processed by hot rolling by passing them through plain or grooved cylindrical rotating rolls to produce plates, sheets, rods, structural sections, and tubes etc.

Rolling process is one of the most important and widely used industrial metal forming operations. It provides high production and close control of the final product. It was developed in late 1500s. It accounts for 90 % of all metals produced by metal working processes.

Rolling steel is a metal forming process in which steel is passed through a pair of rotating rolls for plastic deformation of the steel. Plastic deformation is caused by the compressive forces applied through the rotating rolls. High compressive stresses are as a result of the friction between the rolls and the steel stock surface. The steel material gets squeezed between the pair of rolls, as a result of which the thickness gets reduced and the length gets increased. Rolling is classified according to the temperature of the steel rolled. If the temperature of the steel is above its recrystallization temperature, then the process is termed as hot rolling. If the temperature of the steel is below its recrystallization temperature, the process is termed as cold rolling.

The rolls run on massive neck bearings mounted in housings of enormous strength and driven by powerful electric motors. These are known as mill stands. There are several types of rolling mill stands as given below.

• Two- high stand – It is the basic type of rolling mill stand in which two opposing rolls are used.

• Two-high pullover stand – The rolling steel stock is returned to the entrance for further reduction.

• Two-high stand, reversing – The work can be passed back and forth through the rolls by reversing their direction of rotation. 

• Three-high stand – It consists of three rolls. The upper and lower rolls are driven while the middle roll rotates by friction.This improves the productivity.

• Four-high stand – It has small diameter rolls (less strength and rigidity) are supported by larger-diameter backup rolls. Rolling power is directly proportional to roll diameter. 

• Universal mill stand – This stand has two horizontal rolls and two vertical rolls. Vertical rolls are used to control the width of the work simultaneously.

• Cluster mill or Sendzimir mill stand – In this rolling mill stand, each of the work rolls is supported by two backing rolls.

• Planetary mill – It consists of a pair of heavy backing rolls surrounded by a large number of planetary rolls. Each planetary roll gives an almost constant reduction to the slab as it sweeps out a circular path between the backing rolls and the slab. 

Fujian Putian Geili Machinery manufacturing Co., Ltd was founded in 2006, the registered capital of 20,000,000 yuan. The company is located in one of the city center onn the west side of the Straits Economic Zone, Xianyou Putian. As a professional and experience manufacturer in China, we can supply designing, manufacturing, installation and commissioning of the equipment with "turn-key" service.

 Two high Rolling mill

Effective management of energy in steel plant

In recent years, the need for a more rational and efficient management of energy has emerged as a strategic and urgent issue for an integrated iron and steel plant. Today energy plays an important role in the operation of the steel plant and inefficient use of energy has severe adverse effect on the plant bottom line. In fact, energy costs make up a large percentage of total operating costs. This has made the management of the steel plant to focus its attention on the use of energy in the plant and the efficient management of energy usage has become one of the prime objectives for the management of every steel plant. Active and efficient management of the energy not only helps in the energy conservation and minimization of environmental impact but it is also crucial in ensuring the competitiveness of the steel plant.

Effective management of the energy results into the following.

1. It provides opportunities to decrease the energy intensity/ton of crude steel.

2. It provides best or good practices to utilize energy sources more effectively

3. It provides best or good practices to recover energy (heat, and gas etc.) wherever practical

4. It enables the steel plant to develop plans for plant energy intensity reduction.

5. It helps prioritization of the capital investments for improving the energy efficiency with the biggest impact.

6. It optimizes purchase and consumption of all fuel types and energy inputs.

7. It provides opportunities to reduce carbon di oxide (CO2) and other emissions.

Types of energy used in the steel plant:

Purchased energies: Fuel energies, electricity

Generated energies: Byproduct fuels, electricity

Other energies: Chemical, pressure, steam and hot air

The management of energy in the steel plant has several components which need serious attention. These components are described below.

Quality of energy Quality of raw materialsProcess stabilityInefficient and inadequate maintenance Line losses, leakages and flaringHandling of solid wastesSize of the equipment, etc
Effective management of the energy cannot be done alone either by the energy department or by the individual production shop. It has to be  team effort with the participation of every one.

Fujian Putian Geili Machinery manufacturing Co., Ltd was founded in 2006, the registered capital of 20,000,000 yuan. The company is located in one of the city center onn the west side of the Straits Economic Zone, Xianyou Putian. As a professional and experience manufacturer in China, we can supply designing, manufacturing, installation and commissioning of the equipment with "turn-key" service.

Two high Rolling mill