25-27 April 2022
Conventum Conference Center
Europe/Vienna timezone

Hot working tool steel with bainitic microstructure

26 Apr 2022, 16:10
20m
Room 2

Room 2

Oral Presentation Microstructure, properties & performance Microstructure, Properties & Performance

Speaker

Hans-Günter Krull (Deutsche Edelstahlwerke Specialty Steel GmbH & Co KG)

Description

Usually, tool steels are used in quenched and tempered condition. Due to the phase transition from austenite to martensite and the volume change during the transformation, controlling of distortion might be a challenge. The end user’s demand for high hardness of the final tool leads to a poor machinability.
Engineering steels with bainitic structure are generally based on a low alloying content due to economic reasons, especially the carbon content is rather low compared to tool steels. Bainitic steels require often a controlled cooling to get the desired microstructure and the maximum size to achieve a fully homogeneous bainitic structure is limited to a dimension far below acceptable dimensions of tool steels.
A newly developed steel focusing on a bainitic structure even for bigger dimensions shows a lower hardness at ambient temperature than conventional hot working tool steels, but with a lower temperature dependency. Therefore, at service temperature the mechanical properties are comparable to established grades. Heat treatment is simplified by a simple austenitization and cooling process without special requirement on the cooling rate. Due to a generally lower cooling rate and lower hardness compared to a Q&T process the risk of cracking is reduced, while machinability is improved.
With the combination of good weldability and rather low hardness after rapid cooling, this grade can also be processed in additive manufacturing and is well-suited for a hybrid process of conventional and additive manufacturing.

Speaker Country Deutschland

Primary author

Hans-Günter Krull (Deutsche Edelstahlwerke Specialty Steel GmbH & Co KG)

Co-authors

Philipp Niederhofer Dr Till Schneiders (Deutsche Edelstahlwerke Specialty Steel GmbH & Co KG) Mr Frank van Soest (Deutsche Edelstahlwerke Specialty Steel & Co KG)

Presentation Materials

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