Automotive industry faces a growing demand of improved passenger and environment protection. The weight reduction of the vehicles reduces fuel consumption and CO2 emissions: 100 Kg weight reduction of a passenger car decreases the fuel consumption with 0,3 till 0,5 litre per 100 kilometres. The goal is to reduce the weight while maintaining strength and stability and while improving crash characteristics. To win this challenge, numerous car manufacturers use hot forming processes to produce structural car body parts such as A- and B-pillars, tunnels, front and rear bumper beams, door sills, door beams, side-rails, roof rails and roof frames.
Structural and safety components in passenger car (source: Arcelor Mittal)
Hot forming is more complex compared to conventional forming. By using the hot forming process, parts with higher strength, higher geometrical complexity and minimized spring-back effects can be produced in a much shorter amount of time.
Actually two types of hot forming processes are distinguished: Direct and indirect hot forming. The direct hot forming consists of the following steps:
Heat treatment in furnace (around 950°C – 3 till 10 minutes)
Transfer from furnace to a hot forming press with press- tool
Plastic hot forming (750 – 850° C)
Quenching in the closed, cooled die
The indirect hot forming consists of the following steps:
Plastic forming at room temperature
Transfer from press to furnace
Heat treatment in furnace (around 950°C – 3 till 10 minutes)
Transfer from furnace to a hot forming press with press- tool
Plastic hot forming (750 – 850° C)
Quenching in the closed, cooled die
BLISS-BRET delivers the machines for this hot forming process. The presses are developed in collaboration with the press-users and steel manufacturers.
Hydraulic presses with or without drawing cushion(s) and optional stripper:
· Up to 1200 kW of installed power
· Production speeds up to 750 mm/sec
· Design for hot forming
· Cooling device for the quenching of the blank in the tool
· Moving bolster
· Integration of a heating device and feeding equipment by means of industrial robots
PHS1200 with 900 KVA installed power