Differentiating Hot, Warm, and Cold Forging

Metal forging is a group of different forming processes in which a billet is deformed plastically between certain tooling fixtures through the application of compression force. Forging can be carried out in a wide range of temperature ranges including isothermal, warm, hot, and cold. Forging, as one of the most significant metal processing processes, holds utmost importance, particularly in the iron and steel manufacturing industry. 

Used for the first time around 4000 B.C., forging has been identified as one of the oldest metallurgical procedures. At that time, this procedure was used to make jewelry, coins, and a large number of utensils by hammering different metals using tools made from stones. Modern forging manufacturers across the country and the world still work on the same principles but the age-old hammers and other tools are now replaced with ultramodern high-powered hammers and mechanical presses. Some of the most commonly forged and used products include the following:

• Turbine rotors
• Gears
• Bolts and rivets
• Cutlery
• Hand tools
• Various structural components for machines
• Parts for the aviation and railways
• A range of other transportation equipment

Some of the most prominent components forged by the top steel forging manufacturers for the automotive industry include the following:

• Connecting Rods
• Brackets
• Balancer Cam Shafts
• Helper Spring Plate
• Drive Shafts
• Cylinder Cover
• Rack Piston
• Drop Arm
• Sector Shaft
• Spring Clamp Plates
• Support Arms
• Wheel Hubs

Isolated components are generated through the forging process because grain structure and the metal flow of the material can be effortlessly controlled. Forged objects, parts, or components come with exceptional strength and toughness, and therefore, they are considered to be extremely reliable for highly hostile, stressed, demanding, and critical applications.

Some of the salient characteristics of metal forging

• Forged components have outstanding strength and toughness
• They can be used in critical conditions because of their unshakable reliability
• Modern forging processes produce almost no scrap, therefore, cost-effective for a large number of medium to large production batches
• The forging process is very fast and can create the final part geometry quickly just through a few hammer strokes.

Hot, Cold, and Warm forging at a glance

Cold forging compresses different metals at an ambient temperature, whereas hot forging calls for a high level of heat. The intensity of heat is what distinguishes cold and hot forgings. Hot forging offers the feasibility of creating more complicated and sophisticated shapes in comparison to cold forging.

Hot Forging

Depending upon the type of material to be forged, the temperature range in hot forging might drastically vary. The hot forging process starts with the die heating process so that temperature loss can be avoided during the operation, and also to make sure that no crystallization takes place until the forming task gets completed. Any metal when heated gets more ductile, and at the point when hot metal is squeezed by the dies, a more refined grain is achieved in the structure, resulting in more yield strength as well as ductility. 

Cold Forging

In cold forging, the material is formed into the desired shape through the displacement methodology. At a moderate temperature, a compressive force constricts the metal between a die and a punch till it gets in the outlines of the die. Some of the most common examples of cold forging include the following:

• Rolling
• Pressing
• Drawing
• Spinning
• Heading
• Extruding

Warm Forging

Warm forging, as a manufacturing method, is getting immensely popular across the globe owing to its cost-saving advantages. As for the temperature range of warm forging of steel, it is about 800 to 1,800 degrees Fahrenheit, depending upon the alloy. Nevertheless, the narrower range from 1,000 to 1,330 degrees Fahrenheit is considered a better commercial potential for the warm forging of steel alloys. When compared to cold forging, warm forging scores heavily due to various advantageous reasons. Some of them include the following:

• Reduced tooling loads
• Reduced forging press loads
• Increased steel ductility
• Elimination of the need to anneal before forging
• Favorable, as forged properties often eliminate heat treatment

Caparo’s stature as a leading steel forging manufacturer in India

As a leading steel forging manufacturer in India, Caparo is backed by 3 Closed Die Hot Forging Press Lines that range from 1600 Tons to 6300 Tons. These lines can produce press forgings weighing from 0.5 kg to 50kgs. All press lines work on a unique concept of the Single-Piece Flow Production system, through which the billet or workpiece shearing takes place only when the product is required at the end of the cycle. This renders the highest productivity with no chances of the mix-up of cut metal.

Highlights from the infrastructure area:

• 100% Magnetic Particles Inspection for Safety & Critical Parts
• Integrated Machining lines with necessary SPMs
• Closed Die Hot Forging Integrated Press Lines
• Induction Billet Heaters inline
• With conveyors for material handling
• Dedicated Heat Treatment facility for each line
• Flexible controlled cooling facility available
• Furnaces are capable of Hardening & Tempering, ISO-Thermal Annealing, Normalizing, and Controlled / Slow Cooling.

Engineering prowess at a glance

Caparo holds extensive know-how of product understanding, new-age technology, ultramodern CAD/CAM infrastructure, and outstanding product development expertise. All these things together empower the company to come up with innovation-inspired designs. The company’s design team makes sure that each and every design is integrated with 3D model simulation for better size, weight, and performance optimization.

The set of software that powers the design team includes:

• AutoCAD 2018 for 2D Design and Drawings
• UG NX6 for solid 3D modeling and Drafting
• UG NX6 for CAM programming and Verification
• NC Code for generation of high-speed VMC machines for Tools & Die making

Deform 3D Software is used by the design team for:

• Offline parts development
• Optimizing forging process
• Optimizing raw materials required
• Better utilization of press & dies

Concluding Remarks

Established in the year 2009, Caparo Forging manufactures a comprehensive range of forged and machined products for a variety of automotive and non-automotive applications. The company has a gigantic capacity to produce 8400 MT of finished products per annum. It is the most preferred partner for leading names in the industry such as Iljin, Daimler, Rane TRW, Woosu, AVTEC, Royal Enfield, Delphi TVS, CAT, Simpson & Co. Ltd, and many more.