August 2024 Volume 6

MATERIALS

Task 3: Mixed Load – Wear and Cracking In some cases, forging shops have to deal with dies showing wear and cracking at the same time. In this situation, a tool steel that combines good toughness and sufficient wear resistance has to be selected.

forging has to be stopped, the dies should be tried to keep pre-heating temperature. Lubrication during production can also help increasing die life. Conclusion The international forging industry faces multiple technological chal lenges in order to stay competitive. Changing tools is often causing downtime and lifetime of a die is also contributing significantly to overall parts cost. Clever die material selection of the tool can be decisive here. For special cases, the team of Kind&Co will help setting up tool steel selection for dies, tailored to the process and forged product. Depending on the application and defect pattern, using a care fully selected premium hot-work tool steel from Kind&Co can be very beneficial. Based on experience and close consultation with customers, a significant increase in service life can be demonstrated through the use of premium steels from Kind&Co. By gaining higher volumes of forged parts and lowering down times of the production line caused by die failure, the production costs for every forged part can be lowered with the right tool steel.

Figure 5: Possible premium hot-work tool steel with high toughness and sufficient wear resistance. In this special case, one of our customers has to deal with a deep engraving of a forging die for a specialized commercial vehicle part. The die showed massive wear and cracks in several positions in engraving. The modified H13 used for this application has had a hardness of 55 HRC. By changing to the premium hot-work tool steel CS1 with a hardness of 53 HRC, the target of 6,000 forged parts could be reached without resinking of the die, while the H13 modified die got a resink after 2,000 parts and failed critically after 4,000 parts. Die care – important to keep the inner values of a die. Very often, taking care during manufacturing and running of a die is not taken into account. A proper heat treatment after rough machining is bricklaying for good die performance. Kind&Co provides a tailored heat treatment for every premium hot-work tool steel and uses partner heat treatment shops all over the world, who are able to provide proper heat treating. Prior to a production with a die, pre-heating is essential. A pre heating temperature of 300°F – 360°F is important for every hot work tool steel in order to utilize their material properties. Also important is pre-heating of the die to the core. The difference in temperature from surface to core should be as low as possible. The heating also helps increasing the toughness of a die. For an H13 tool steel, the toughness is two times higher at working temperature of 390°F, compared to room temperature. Pre-heating by flame is hard to control and not evenly pre-heating the die. If possible, pre-heating by placing the dies in a furnace is recommended. As soon as a forging press faces malfunction and

Denis Livree Werkstoffingenieur Anwendungstechnik Kind & Co. Edelstahlwerk GmbH & Co.

Jan-Philip Heil Engineer - Application Specialist Kind & Co. Edelstahlwerk GmbH & Co.

FIA MAGAZINE | AUGUST 2024 32