DI-MC 550 B

With regard to its high toughness, DI-MC 550 can generally be well cold formed, i.e. 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.

DI-MC 550 can be delivered:

DI-MC 550 can be flame cut in all thickness ranges without preheating. Plasma and laser cutting can also be carried out without preheating for typical thickness.

DI-MC 550 has an excellent weldability if the general technical rules are observed (EN 1011 has to be applied analogously). The risk of cold cracking is low. The choice of the appropriate preheating temperature depends on the construction, plate thickness, welding heat input, chosen welding process, welding filler materials and base materials (basic quality B and low temperature quality T). From experience, an appropriate choice of these parameters allows omitting the preheating. To avoid hydrogen induced cold cracking, only filler materials, which add very little hydrogen to the base metal, may be used (up to 5 ml/100 g DM according to ISO 6390).

The low content of carbon and other alloy elements leads to favourable toughness properties in the heat affected zone, even with high heat inputs. Depending on the chosen welding process, welding filler material as well as toughness requirements in the heat affected zone, it permits cooling temperatures (t8/5) above the limiting values of 25 s as stated in EN 1011-2 and SEW 088.

For thermomechanically rolled steel the report CEN/TR 10347 recommends maximum flame straightening temperatures.

If special 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 data sheet is a product description. This data sheet is updated at irregular intervals. The current version is relevant. The current version is available from the mill or as download at www.dillinger.de.

Welded joints of DI-MC 550 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 air. The holding time should not exceed 1,5 hours (even if multiple operations are carried out). For particular 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) The impact properties and the tensile properties shall be verified for each mother plate.

Identification: Unless otherwise agreed, the marking is carried out via steel stamps with at least the following information:

The entire processing and application techniques are of fundamental importance to the reliability of the parts and assemblies made from this steel. The user should ensure that his design, construction and processing methods are aligned 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 and SEW 088 should be observed.

Unless otherwise agreed, the specifications will be in accordance with EN 10163, class A2.

Tensile test and impact tests are carried out once per heat, 60 t and thickness range as specified for the yield strength according to table 5 of EN 10025-4. Tests on every mother plate are possible on request (see option 1).

The test pieces are taken and prepared according to part 1 and 4 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. The impact test will be carried out on Charpy-V-specimens in accordance with EN ISO 148-1 using a 2 mm striker. Unless otherwise agreed, the test will be performed according to EN ISO 148-1 at a temperature of -20 °C for the basic quality B and at -50 °C for the low temperature quality T on longitudinal test pieces.

Unless otherwise agreed, the test results are documented in a certificate 3.1 in accordance with EN 10204.

Unless otherwise agreed, DI-MC 550 meets the requirements of class S1E1 in accordance with EN 10160.

Unless otherwise agreed, tolerances are in accordance with 10029, with class A for the thickness. Flatness deviation may be agreed on request.