Mill rolls are essential in the metal working industry. They are manufactured to an optimum hardness to resist wear and prevent marking. Forged steel roll is a type of rolling mill rolls. The roll has a microstructure that allows the surface finish to be resistant to thermal shock and a hardness depth prevents rehardening in subsequent applications.
Firstly, we give some basic knowledge about the forged steel roll including the definition, types, feature, chemical composition, etc.
What Are Forged Steel Roll
Forge steel roll provides a mill roller solution for rolling mill. It is one of the most wear parts during the rolling process. It is mainly made of forged steel. It is forged in hydraulic presses for high toughness and pureness, widely used in cold rolling mill, steckel mills and continuous hot strip mills. As different rolling mills have specific requirements and various rolling conditions, different alloy elements can be added into the steel for higher performance of the roll. The roll covers forged steel work roll or intermediate roll, forged steel back up roll.
Forged Steel Roll
Definition
The forged steel rolls are made from steel ingots by forging, which can solve metallurgical defects such as loose and shrinkage holes in the ingot, and crush the coarse cast structure to obtain superior quality roll with high resistance.
The production process includes smelting, ingot casting, forging, post-forging heat treatment, rough processing, final heat treatment and finishing.Feature
High Toughness
Surface Hardness Uniformity
Fatigue Resistance
High Hardness And Durability
Application
It is mainly used as strip rolling mill working roll and backup roll and is a high speed roll (HSS roll) for tandem and reversing cold reduction mills.
Forged Steel Back Up Roll
Definition
The forged back up roll is a mill roll that supports the work roll and intermediate roll for the purpose of avoiding deflection of the work roll and affecting on the yield and quality of the plate and strip rolling mill. This is the key function of back up roll to ensure the operation of the whole rolling mill. The common materials are 9Cr2Mo, 86CrMoV7, 70Cr3Mo with 0.80% to 0.95% carbon content 2% Cr content. The diameter of roll body ranges from 350mm-1600mm.
Feature
High Rigidity
The back up roll requires high rigidity to ensure the smallest deformation for supporting work roll.
Good Fatigue Resistance And High Peeling Resistance
The backup roll always need to support work roll or intermediate roll. Overloadig cause the subcutaneous miccrocrack propagation and roll body peeling off. So the excellent fatigue resistance is necessary.
High Surface Hardness With Good Hardness Uniformity
Outstanding surface hardness ensures the exceptional wear resistance and can reduce the formation of concave roll shape.
Excellent Yield Strength And High ToughnessTo guarantee the long service life, the deep hardened layer of roll body, good strength and toughness of roll neck and roll body and strong anti-accidents are required.
Application
Forged steel back up roll is applicable for 4-Hi mill, 6-Hi mill, and other some small mill.
Usually electric motors are used to start diesel engines. When meet the lack of maintenance, no charge of battery, or power is down, the engine will not start normally. When in an emergency occasion, the consequence is serious. Mechanical starter, which is an efficient non-electric engine starting device, can solve the starting problem when the battery is low and can start a diesel engine without electricity, purely depends on the hand crank system for engine start.
What’s The Mechanical Starter
The mechanical starter is a device to start the engines without electricity. Electric batteries are one of the most common power sources for engine start. But the batteries always can’t work in the extreme low temperature, damp and harsh environment and the hand crank starter will be the ideal choice. This is the reason why marine, offshore oil, underground mining need a mechanical start device.
Advantages of Mechanical Starter
1.Effective In Extreme Low Temperature
When in a cold weather, cranking an engine is a hard work and takes much more energy with the thickened viscosity of the oil. The engine may not crank fast enough to start. The low temperature will slow down its chemical processes of a battery, which makes the power becomes lower.
The mechanical engine starting system doesn’t require the battery and is a mechanical device which only relies on manpower can start the diesel engine with displacement up to 50L.
2. Independent Startup System
Mechanical engine starter has an independent starting system does not require hydraulic, pneumatic nor electricity and no auxiliary equipment is required.
3. Simple Hand Crank System
Mechanical starter has an important back up solution when everything else fail, an option for hand crank charging. The operation is simple with winding the handle and pushing the release lever, then the starting process being completed. The maintenance is also easy.
4. Environmentally friendly
The mechanical starting system has no energy consumption and no pollution emissions. Used batteries will pollute the environment and the decay of the battery will produce toxic substances
5. Lightweight And Minimizing Space
With simple manual crank system, the mechanical engine starter will not take up much space. It’s lightweight and easy to carry.
The mechanical starter solves the problem that the engine can’t start when the power of battery is low or out of power. It has a simple manual crank system with flexibility and reliability.
1. Carbon Content
The carbon content of hot-rolled steel can be slightly higher than that of cold-rolled steel. The density is the same when there are little differences in the components.
2.Density
The density and composition of hot rolled steel can be checked through looking for various steel to find the specific one. Cold rolled steel has high hardness and relatively has difficult for processing, but it is not easy to deform and has high strength.
3. Production Process
The production process of hot-rolled steel and cold-rolled steel is different. Hot rolling steel is rolled at high temperature and cold rolling steel is processed from hot rolled steel at normal temperature. Generally speaking, cold rolled steel has better strength and hot rolled steel has better ductility.
What Are The Differences Between Hot Rolled Steel And Cold Rolled Steel
1.The Surface
The cold steel plate is cold rolled and the surface has no oxide scale with good quality. The hot steel plate uses hot rolled processing technique with oxide scale on the surface.
2. Toughness & Stretchability
Hot rolled steel has poor toughness and the price is low, while cold rolled steel has good stretchability and toughness, but the price is more expensive
3.Mechanical Properties
The cold rolled steel has much better mechanical properties than hot rolled steel.
4. Formability
Since the surface of cold rolled steel is better than hot rolled one, the forming effect also better than that of hot rolled steel.
5. Torsion resistance
Hot rolled steel has higher free torsional stiffness than cold-rolled steel, so the torsional properties of hot-rolled steel are better.
6. Smoothness
The smoothness of cold rolled steel sheet is better than that of hot rolled sheet.
Overall, cold rolled steel has better performance than hot rolled steel, but cold rolling process will cost more and the cold rolled steel has higher price than that of hot rolled one. People should choose the suitable one according to their needs. No matter what types of the rolling is, the mill rolling process plays an important role in steel making and mill roll is essential for the perfect dimensions.
Maybe different people have different views on hot rolled steel and cold rolled steel. Hope the simplified explanation will help people learn more about the two types of steel or steel plate.
The circumstances for using spring start motor
1. Extreme temperature and damp
Spring starter motor needs only hand cranking and releasing spring energy without other power consumption .Its resistances to damp and extreme temperatures make them ideal for marine applications.
2. Non-electric
Spring starter only requires manpower, no hydraulic, pneumatic or electrical infrastructure required. Don’t need to worry the battery has no charge and can be applicable for the dangerous area with prohibition of electric start.
3. Emergency
Spring starter motor can be used as the most suitable backup starting device with the storage spring energy for the emergency like fire-fighting, rescue, marine emergency, military, etc.
How the spring starter motor works
When needs to start a diesel engine, Pull the winding handle of the starter to make the release mechanism store in the energy for ready use. Wind the handle to turn in the prescribed direction to achieve the required storage energy and push the lever to release potential spring energy. Then the diesel engine can be started.
Two types of spring used for spring starter motor
Disc Springs
The springs are compressed by means of a ball screw
Feature:
simple to use
small space required
long-span life
High output torque
Power Springs
The springs are coil springs which are wound up
Feature:
High number of output revolutions
Compact
About Dalin Spring Starter
Dalin spring starter is manufactured by Chongqing Starting Power Unit Co., Ltd which was established in 2008. The company is specialized in the solutions for emergency of engine start and developed a special mechanical starter-Dalin spring starter, applied to military, fire, marine emergency, telecommunications, etc. It has a professional R & D team leading by senior engineer for superior quality products with advanced technology and rigorous services.
Displacement ranges from 0.5L-38L, which is the world record starting power of spring starter motor.
Single spring starter can start 6 cylinders in-line engine with displacement up to 19L, 16 cylinders V-type engine with displacement up to 30L. 0 group system can start up to 50L.
Spring starter group system can start 6 cylinders with the displacement up to 26L, 12 cylinders start up to 38L
Reliability
All products are tested by the unique spring starting test bench with experiment of more than 3000 starting cycles, ensuring all products have
detailed test data. The spring starter has the long-life span of more than 10 years according to customer’s feedback.
Cost Performance
All parts are made from mature material, produced by qualified heat treatment and machining process. On same power level of the starters, Dalin spring starter costs less than similar competing starter.
Simple and Safety Operation
It’s simple to operate. There’s not any auxiliary equipment to be configured, only adopting mechanical structure. The crank will not fly off or kick back during operation, which guarantee the safety of operation.
Services
Dalin spring starter provides excellent after-sale service with a professional service team，which can solve the problems of customers at any time.
Contact information
Sales: Julie He(Ms.),
Tel/Whatsapp/Wechat: +86-13637706003
Email: sales1@cqstart.com
Marketing: Harland Wang(Mr.)
Email：sundayritian@cqstart.com
Dalin spring starter motor, as a mechanical engine start device, provides a powerful and economical starting option for customers who need a simple device for the backup of their electric engine starter.
Hot rolling and cold rolling are the two main processes for the most steel or steel plate making, which have great influences on the structure and properties of the steel. A better rolling mill roll will bring more superior quality steel. Which one is better between the hot rolled steel and cold rolled steel?
Some information about the hot rolled steel and cold rolled steel is introduced.
Hot Rolled Steel
Definition
Hot rolled steel is the finished product through directly processed on the steel mold in the steel furnace with exceptionally high temperatures, rolling with the hot mill roller which can make sure the dimensions of the steel sheet according to the requirements., then coiled and cooling. The main steel rolling type is hot rolling.
Advantages
Compact the steel structure and improve the mechanical properties.
Disadvantages
1.After hot rolling, delamination occurs, when the non-metallic inclusions in the steel are pressed into thin sheet. Delamination greatly deteriorates the tensile properties of the steel.
2. Residual Stress caused by uneven cooling. Residual stress is internal self-phase equilibrium stress without external force. Hot rolled steel may have negative effects on deformation, stability, fatigue resistance, etc.
Cold Rolled Steel
Definition
The cold rolled steel bar is obtained by cold working of the hot-rolled steel, such as cold drawing and stretching at a normal temperature. Cold rolling is often used for the production of small sections and steel sheets.
Advantages
Cold rolled steel bar has fast forming speed and high output. It can be made into a variety of cross-sectional forms to meet the requirements of the different use conditions. Cold rolling mill can make the steel have a large plastic deformation.
Disadvantages
Torsion is prone to occur under bending. Bending and torsional buckling is easy to occur under compression. So the torsional performance of cold-rolled steel is poor, and the ability to withstand concentrated loads is weak.