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Hot stamping (also known as press hardening, hot press forming, or hot forming die quenching) is a relatively new
;Direct Process:
The unformed blank is heated in a furnace, formed in hot condition (state 2 in below figure), and quenched in the die to achieve the required properties.
;Indirect Process:
The blank is formed, trimmed, and pierced in cold condition (i.e., state 1 in below figure). It is later heated and quenched in a die to get high strength properties.
Selection of the process depends on part complexity and blank coating ( Zn based coatings typically require indirect process). In either method, the blank is formed in a much softer and formable state and is later hardened in the dies, which have drilled cooling channels. A typical hot stamped components has 1000 MPa (145 ksi)
Compound StampingPrecision Metal Stamping
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technology
Technology is the application of knowledge to reach practical goals in a specifiable and Reproducibility, reproducible way. The word ''technology'' may also mean the product of such an endeavor. The use of technology is widely prevalent in me ...
which allows ultra-high strength steels (typically 22MnB5 boron steel) to be formed into complex shapes, which is not possible with regular cold stamping operations. This process is commonly used for the production of automotive body in white
Body in white (BIW) is the stage in automobile manufacturing in which a car body's frame has been joined together, that is before painting and before the motor, chassis sub-assemblies, or trim (glass, door locks/handles, seats, upholstery, elect ...
components because its advantages align with the design criteria of modern passenger vehicles.
Methods
;Direct Process:
The unformed blank is heated in a furnace, formed in hot condition (state 2 in below figure), and quenched in the die to achieve the required properties.
;Indirect Process:
The blank is formed, trimmed, and pierced in cold condition (i.e., state 1 in below figure). It is later heated and quenched in a die to get high strength properties.
Selection of the process depends on part complexity and blank coating ( Zn based coatings typically require indirect process). In either method, the blank is formed in a much softer and formable state and is later hardened in the dies, which have drilled cooling channels. A typical hot stamped components has 1000 MPa (145 ksi) Yield Stress
In materials science and engineering, the yield point is the point on a stress-strain curve that indicates the limit of elastic behavior and the beginning of plastic behavior. Below the yield point, a material will deform elastically and w ...
and 1500 MPa (215 ksi) Ultimate tensile strength
Ultimate tensile strength (UTS), often shortened to tensile strength (TS), ultimate strength, or F_\text within equations, is the maximum stress that a material can withstand while being stretched or pulled before breaking. In brittle materials t ...
.
Advantages
Higher strength steels may help reducing the weight by downgaging (i.e., use of thinner sheets), while increasing thecrashworthiness
Crashworthiness is the ability of a structure to protect its occupants during an impact. This is commonly tested when investigating the safety of aircraft and vehicles. Depending on the nature of the impact and the vehicle involved, different crit ...
. However, one problem with many high strength steels is that their formability is generally lower than milder grades. In addition, springback and die wear also cause problems as the forming stresses and contact pressures are higher.Billur, E. & T. Altan, "Challenges in Forming Advanced High Strength Steels", in Proceedings of New Developments in Sheet Metal Forming 2010, pp285-304, May 2–4, Stuttgart, Germany (2010).
References
External links
Compound Stamping
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