DIWETEN 460+M – Premium Fine‑Grained Structural Steel with Enhanced Corrosion Resistance

The steel can especially be used in steel constructions for bridges and high-rise buildings where a higher strength weathering steel with good weldability is demanded.

DIWETEN 460+M can be cold formed as any comparable structural steel in accordance with EN 10025, i.e. formed at temperatures below 580 °C. Cold forming is always related to a hardening of the steel and to a decrease in toughness. This change in the mechanical properties can in general be partially recovered through a subsequent stress relief heat treatment. Flame cut or sheared edges in the bending area should be ground before cold forming. For larger cold forming degrees we recommend consulting us prior to ordering.

Atmospheric corrosion resistance means that the steel - due to the chemical composition - presents a higher resistance against atmospheric corrosion in comparison to unalloyed steels because a protective coating which protects the surface and decelerates the normal corrosion process is formed on the surface and influenced by the weather. This property is defined by the weather resistance index I > 6.0 in accordance with ASTM G101. Generally, the corrosion velocity decreases with increasing service life. Even after the formation of the patina, a total stop of the corrosion process is not achieved. However, the patina offers - in comparison to unalloyed steels - a better protection against atmospheric corrosion in industrial, city or rural atmosphere, which enables the application of uncoated steels under certain circumstances. Initial formation, time of development and protective effect of the patina on steels with improved atmospheric corrosion resistance are extremely depending on the constructional design and the atmospheric and environmental conditions in the respective case.

In any case, usual constructional standards for the construction with steels with improved atmospheric corrosion resistance are to be observed, as i.e. the German guideline DASt 007 (“Delivery, fabrication and application of steels with improved atmospheric corrosion resistance”).

In addition, the weather resistance index of I > 6.0 in accordance with ASTM G101-04 (2015) is valid.

I = 26.01 · (% Cu) + 3.88 · (% Ni) + 1.2 · (% Cr) + 1.49 · (% Si) + 17.28 · (% P) – 7.29 · (% Cu) · (% Ni) - 9.10 · (% Ni) · (% P) – 33.39 · (% Cu)2.

Thermomechanically rolled (short designation +M).

General technical delivery requirements: Unless otherwise agreed, the general technical delivery requirements in accordance with EN 10021 apply.

DIWETEN 460+M has despite its higher strength and weathering property a good weldability if the general technical rules (see EN 1011) are respected. However the hardenability of the steel is increased due to the Cu and Cr alloying. Owing to the low carbon content oxygen cutting, plasma and laser cutting can be carried out up to large thickness without preheating. The preheat conditions during welding have to be adapted to the slightly increased carbon equivalent compared to non- weathering thermomechanically rolled steels. If necessary, the corrosion resistance of the welding deposit has to be assured by selection of adequate weld metals or other anti-corrosion measures.

If particular requirements, which are not covered in this material data sheet, are to be met by the steel due to its intended use or processing, these requirements are to be agreed before placing the order.

The information in this technical data sheet is a product description. This material data sheet is updated at irregular intervals. The current version is available from the mill or as download at www.dillinger.de.

Welded joints of DIWETEN 460+M are usually used in welded condition. If a stress relief heat treatment is necessary, it is carried out in the temperature range between 530 and 580 °C with cooling in still air. The holding time should not exceed 4 hours (even if multiple operations are carried out). For differing heat treatment requirements we recommend consulting us prior to ordering.

Hot forming, i.e. forming at temperatures above 580 °C, leads to changes in the original material condition. It is impossible to re-establish the same material properties that had been achieved during the original manufacture through a further treatment. Therefore hot forming is not permitted.

1) Tensile and impact test on each mother plate,

2) Supplementary Charpy-V-test: absorbed energy KV2 27 J at -50 °C as the average of 3 tests and minimum single value of 19 J, applicable in the sense of S460J5W+M.

DIWETEN 460+M can be delivered in thicknesses from 8 to 150 mm according to Dillinger delivery program.

DIWETEN 460+M is certified as DIWETEN 460+M/S460K2W+M or with the order option 2 as DIWETEN 460+M/S460J5W+M in thicknesses up to 150 mm. The CE-marking certificate is issued in accordance with EN 10025-1, unless otherwise agreed.

The entire processing and application techniques are of fundamental importance to the reliability of the products made from this steel. The user should ensure that his design, construction and processing methods are with the material, correspond to the state-of-the-art that the fabricator has to comply with and are suitable for the intended use. The customer is responsible for the selection of the material. The recommendations in accordance with EN 1011-2, guideline DASt 007, SEW 088 as well as recommendations regarding job safety in accordance with national rules should be observed.

Surface quality: Unless otherwise agreed, the specifications will be in accordance with EN 10163-2, class A2.

Ultrasonic testing: Unless otherwise agreed, DIWETEN 460+M meets the requirements of class S1E1 in accordance with EN 10160.

Tensile test at ambient temperature – transverse test specimens

Tensile test and impact tests are carried out with respect to EN 10025-5 once per heat, 60 t and thickness range as specified for the yield strength. Tests on every mother plate are possible on request.The test pieces are taken and prepared according to part 1 and 5 of EN 10025. The tensile test is carried out on specimens of gauge length Lo = 5.65⋅√So respectively Lo = 5⋅do, in accordance with EN ISO 6892-1. Unless otherwise agreed, the impact test is carried out at -20 °C (at -50 °C for option 2) on longitudinal Charpy-V-specimens in accordance with EN ISO 148-1 using a 2 mm striker. Unless otherwise agreed, the test results are documented in a certificate 3.1 in accordance with EN 10204.

Unless otherwise agreed, tolerances are in accordance with 10029, with class A for the thickness.