Drop forging manufacturer

sales@dropforging.net

Home » News » Page 8
Differences between drop forging and press forging
Drop forging is when half of the die is dropped from a height onto the other half of the die,which will contain the hot metal workpiece to be formed. Drop forging is more suitable for mass production.Press forming is instead of dropping half the die onto the other half the two halves are put together and pushed together under a large pressure (up to about 10000 tons) forming the object.the difference is that drop forming leaves the centre of the metal not so hard as the outside,but press forming gives more uniform hardness for larger components.Of course,drop forging and press forging are defined in term of two kinds of forging methods.We could also differ forgings from its temperature,such forgings are named into cold forging,warm forging and hot forging.(See cold forging vs warm forging vs hot forging).
Forging formings of metals according to temperature can be divided into cold deformation (cold forging),warm deformation (warm forging) and thermal deformation (hot forging).The microstructure and mechanical properties influences on forgings of these different forging processes are also different.

1)Cold forging:refers to blanks processed below the recrystallization temperature.

Characteristics of cold forging:high dimensional accuracy,good surface roughness,good working conditions and high production efficiency.So cold forging can replace machining sometimes.Cold forging can make metal reinforcement,improve the strength of parts.So it is applicable to aluminium and plastic parts alloy, copper and alloys,low carbon steel,medium carbon steel,low alloy steel which the deformation resistance is small under room temperature.But when cold plasticity,metal deformation resistance is big,with poor plasticity,and contains accumulation of residual internal stress,needs to continue deformation after intermediate annealing.Nevertheless,the advantages of cold deformation technology makes it is more and more widely used.

Crank shaft is main rotating parts of engine, is installed on the connecting rod,can undertake the (reciprocating) up and down movement into circulation movement (rotation) of connecting rod. Is an 
important part on the engine, and its material is made of carbon steel or nodular cast iron, there are two important parts of crankshaft:main journal, connecting rod journal,(and other). Main journal is installed on the cylinder block, connecting rod connected with the big hole, neck connecting rod small hole is connected to the cylinder piston, is a typical slider-crank mechanism. Lubrication of the crankshaft is mainly refers to the lubrication of bearing between the rocker arms and the lubrication of two fixed point.The rotation of the crankshaft is the power source of the engine. Is also the driving force of the whole mechanical system.

Crankshaft fracture is the serious fault of the engine,and fracture usually occurred in the postions of connecting round corners between crank pin,main journal and the crank arm or other stress concentrated sections,like journal oil hole position.
The crankshaft is an important part in automobile engine, it will cooperate with connecting rod and change gas pressure roled in the piston into the rotation of the power,to the transmission mechanism of underpan,drive distribution agencies and other auxiliary devices.

When crankshaft is working,it will be forced under gas pressure,inertia force and  inertia moment.Meanwhile,the crankshaft is high speed rotating parts,therefore,requires the crankshaft has enough stiffness and strength, has a good ability to withstand the shock load, good wear resistance and lubrication.

Crankshaft has mainly following two kinds of damage forms in working process:One is fatigue fracture.Will first produce fatigue crack at the position of shaft neck and round corner,then extend to the depths of crankshaft and causing final fracture.Second way is causing serious wear and tear on the surface of the journal(especially in the connecting rod journal).So the crankshaft should have a higher fatigue strength and good wear resistance.
Chinese output of closed die drop forgings is always in the first place in the world.These closed die forgings are manufactured mostly using hot die forging method.And the output of automotive forgings accounts for about 67% of all the closed die drop forgings,so in the production of automotive forgings, closed die drop forging still accounts for absolute proportion.With the rapid increasing of closed die drop forging,the energy consumption is also growing in a fast speed.In recent years,the comprehensive energy consumption of closed die drop forgings has reached more than several million tons coal,and there is large amount of waste gas and dust produced also.So to project environment,we must push on green manufacturing.Below are the solutions available for drop forging manufacturers:

1.Choose green material 
Give preference to continuous casting of steel rolling,non quenched and tempered steel.The yield of continuous casting is higher than that of die cast steel,saving 10-15% energy consumption,and save the intermediate reheating energy consumption and reduce the cost.Closed die drop forgings using non quenched and tempered steel saves energy consumption of second heating and high temperature tempering,saving 0.7 KW power per kilogram.

Drop forged conveyor chains are widely used in bulk material handling of products such as grain, coal and ash. Also known as drop forged scraper chains they are typically fitted with flights or special 
attachments. The chain links themselves are forged from specially selected alloy steel and then precision machined to close tolerances.
 
When you require continuous flow (en-masse or drag conveying) and the material is being moved slowly within the casing, then a drop forged conveyor chain with attachments matched to the materials being moved will be a good option.

In drop forging production,we will need making forging dies first for closed die drop forgings.And we call the material of drop forging dies is die steel.So to start a new product,drop forging manufacturers have to buy die steel first.Selecting a die steel supplier is a key decision for all parties, including the die maker,the die user and the end user.Thanks to superior material properties,ourcustomers get reliable tools and components. Our products are always state-of-the-art. Consequently, we have built a reputation as the most innovative dies producer in the world.
We produce and deliver high quality drop forgings to more than 100,000 customers in over 100 countries.Together we secure our position as a world-leading supplier of dies and drop forgings.
closed die and open die forging
In modern society,forging industry is involved in various industries for construction machines,agricultural machinery,automotive,oilfield equipments,ect.Steel billets could be processed by various forging 
processes,among them the common used forging ways are closed die forging and open die forging.Although these two forging methods all belong to forging,it is not difficult to tell the difference between closed die forging and open die forging.The biggest difference of them is forging dies.Now let us have a deeper comparison on the differences between them.

Definition
Open die forging is also named free forging,means metal billets compressed under external compressive force and deformed to desired demensions or shapes in a free way without forging dies.Closed die forging,also referred to impression die forging,is a process that heated by medium frenquency induction heating furnace to high temperature and forged between upper and lower dies to get expected shapes like the drawing.
Although there are a variety of advantages of drop forging technology compared to other metal forming processes,there may still exsit some defects in hot forging process.Such drop forging defects can be split into two broad types:geometrical defects and non geometrical defects.

Geometrical defects of drop forging
*Laps and folds:Laps and folds are produced due to improper design of drop forging dies,making the laps created onto the final component which is rather undesirable as make irregular surface finish and also may weaken the product for internal or external cracks.
*Unfilled defects:There may exsit some sections of die cavity not completely filled by the flowing steel.This defects happen due to the improper design of drop forging dies or not using the right forging process.
There are different types of forgings,drop forging(closed die forging and open die forging),cold forging,samless rolled ring forging.So forging can generally divided into hot forging and cold forging.Cold forging is a forging process mufacturing in room temperature,however hot forging is a forging process in high temperature,so it is also referred to as drop forging.We can use hot forging to produce a wide range of parts in most metals.So we may be wondering why drop forging is hot forging,not cold forging?
hot forging
Forged steel is a forged process made in steel.Early forged steel types were developed in China and Persia.Traditionally forged steel is manufacturered by  a smith.Since 1800s,modern forged steel was started.To make forged steel,workers have to heat metals to high temperature so that it could be easily shaped into desired dimensions.Today forged steel is used in a number of industries.

Benefits of forged steel
  • Forged steel require an initial cost for the design and making of dies.But it has low recurring cost for each parts,so drop forging gradually become more economical with large volume.
  • During drop forging process,metals are shaped to follow the designed shape of part while its internal grain deforms.Then,the grain is continuous throughout the part and make forged steel parts with improved strength.Therefore,forged steel has higher strength to weight ratio compared to cast steel,at least 20% higher.
  • Forged steel is the right alternation of aluminuum for its low cost in many applications.And forged steel has three times as strongth as aluminium although it is much heavier.
Background
For the advantages of drop forging,such as it can bear high power,this process is widely used for all industrial manufacturing.In all the metal forming process,we can say drop forging is the best solution for your steel parts.So today more and more buyers use drop forging as the production process,especially for those components in large production runs.Most drop forging manufacturers supply OEM service for their customers,so buyers can forge any shapes they like,of course,such shapes must comply with drop forging technology and the dimensions can not exceed the range of the largest forging press allows.There are many drop forging companies all over the world,and buyer can choose to custom drop forgings in any countries(USA,UK,Australia,China,ect) they like.In comparison,they prefer to buying in China for the low price.But due to the lack of understanding of Chinese drop forging industry,buyers do not know how to make the parts in China.