customer information - Dillinger Hütte GTS

customer information - Dillinger Hütte GTS

EN 10028-4:2003-06

Flat steel products for pressure purposes

Part 4: Nickel-alloy steels with specified low temperature properties

Main changes compared to the preceding edition:

1. The manufacturing of the steel grades 11MnNi5-3 and 13MnNi6-3 by normalizing rolling

instead of normalizing in furnace is no longer permitted.

2. The maximum permissible deviation of the product analysis from the heat analysis concerning

S contents is generally reduced. In case of the steel grade X7Ni9 this also applies to the P value.

3. The designation of the 5%Ni-steel grade 12Ni19 has been changed to X12Ni5.

4. The 9%Ni - steel grade X8Ni9 can be delivered (like before) with a minimum tensile strength of

640 MPa or 680 MPa respectively.

In the former standard the two minimum tensile strength versions “HT640” and “HT680” were also

differing in the minimum impact values of 27 J or 50 J respectively at – 196 °C for Charpy-V

transverse test pieces. As the heat treatment was not clearly defined for the HT640 grade there was

the danger of mixing up the two versions.

In the new edition the minimum impact value is increased from 27 J to 40 J for“640”and the

delivery condition is integrated into the designation of the steel grade. There are now the following

clearly determined possibilities (X7Ni9 is shown to complete the picture):

grade delivery condition Rm (min.) Ch-V transverse at

– 196 ° C (min.)

X8Ni9 + NT640 +N plus +NT 640 MPa 40 J

X8Ni9 + QT640 +QT 640 MPa 40 J

X8Ni9 + QT680 +QT 680 MPa 50 J

X7Ni9 +QT 680 MPa 80 J

5. The maximum plate thickness for the steel grades up to 3.5 % Ni (11MnNi5-3, 13MnNi6-3,

15NiMn6 and 12 Ni14) is increased from 50 mm to 80 mm.


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