Stahl-Eisen-Werkstoffblatt (SEW) 605 - Von Warmformgebungstemperatur kontinuierlich abgekühlte Stähle mit bainitischer MikrostrukturStahl-Eisen-Werkstoffblatt (SEW) 605 - Von Warmformgebungstemperatur kontinuierlich abgekühlte Stähle mit bainitischer Mikrostruktur

SEW 605 – From hot-working temperatures continuously cooled steels with bainitic microstructure

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Description

Reducing the weight of car components has led to more filigree parts and the use of stronger materials. Conventional solutions with quenched and tempered steels not always fulfil the wishes concerning technical reliability, economics and
environmental friendliness. Continuously cooled bainitic steels as obtained from hot-working in the austenite phase are sometimes clearly better balancing these aspects which has led to a successful introduction into car components during
the last decade. This trend is reflected in a variety of commercially available bar and wire rod products. To guarantee the needed hardenability these products are characterized by elevated manganese contents, sometimes in combination
with chromium, molybdenum and nickel. Such steels are not described in any existing material standard today. As an orientation to customers the present SEW standard gives a general description of this new class of steels. Considering naturally cooled steel products the cooling rate will vary depending on part geometries (or bar diameters). To reach constant properties steel compositions (in particular manganese and chromium) are adapted to the respective natural
cooling rates.