Dillinger high-strength DILLIMAX quench-hardening plates
DILLIMAX is one of Dillinger's proprietary steels and is used to produce high-quality quenched and tempered plates. The foundation for this is laid in the steelmaking plant, where high-strength DILLIMAX steels are subjected to vacuum-stream degassing. This process – combined with sophisticated secondary metallurgy – reduces undesirable impurity elements, such as sulphur, for example, to a minimum.
A high-grade plate, particularly in greater thicknesses, needs under all circumstances sufficiently thick and homogeneous primary material. Dillinger has the capability for casting this primary material to so-called slabs up to record thicknesses of 600 mm, using continuous casting.
The slab is then rolled into a plate in the rolling process. Extraordinary roll-separation forces of up to 108 MN (approx. 11,000 t) act during this process. Here, the rolling-pass schedule, i.e. the temperature-dependent sequence of rolling operations, is decisive. Rolling takes place in the largest possible steps, so-called "passes". This principle of "high-shape rolling" deforms not only the plate surface, but also its centre. Such deformation in the centre generates the most homogeneous plate possible from the surface through into the plate centre.
Out-of-the-ordinary mechanical strength is achieved via treatment in quenching and tempering systems (hardening quenches). The plate is firstly cooled extremely quickly and under controlled conditions using water. This creates a hardened microstructure across the entire plate surface. In the DILLIMAX steels, great demands are also made on toughness. For this reason, another heat treatment operation, tempering, then follows. The microstructure in the plate is thus stress relieved. At the same time, hardness and mechanical strength are adjusted to the required values and toughness is raised to a high level. This extremely good toughness is used as a safety margin under extreme stresses. This is vital in the case of thick-walled and welded structures.
DILLIMAX steels are thus coming ever more into use in ever larger machines, conveying systems and lifting equipment, including giant cranes.
Steel grades – an overview:
Q+A oder Q+T: Quenched + tempered (Water-quenched from austenitisation temperature
(>Ac3 ≈ 900° C) + additional annealing)
Ms: Martensite starting temperature
γ: Austenite
α: Ferrite
Christoph Dickmann
Sales Earth moving & Mining equipment, Heavy Machinery, Mold & Die construction
Tel.: +49 6831 472385
Fax: +49 6831 47992681
Stefan Ackermann
Sales Stockists & Steel Service Centers
Tel.: +49 6831 472195
Fax: +49 6831 474580
© Dillinger
Aktien-Gesellschaft der Dillinger Hüttenwerke, Werkstraße 1, 66763 Dillingen/Saar, Telefon: +49 6831 47 0, Telefax: +49 6831 47 2212, Sitz: Dillingen/Saar, Registergericht: Amtsgericht Saarbrücken HRB 23001, Vorsitzender des Aufsichtsrats: Reinhard Störmer, Vorstand: Stefan Rauber (Vors.), Joerg Disteldorf, Daniël Nicolaas van der Hout, Dr. Peter Maagh, Markus Lauer, Jonathan Weber
Imprint
Privacy policy
Copyright © 2016 Dillinger. All rights reserved.
Imprint
Privacy policy
Copyright © 2016 Dillinger. All rights reserved.