Views:24 Author:Site Editor Publish Time: 2017-10-25 Origin:Site
DIN2391 Standard of seamless precision cold drawn or cold rolled steel pipes is similar as the standard EN10305-1. It is wildly used in motor front and rear shock absorber. And automobile parts, gas spring of furniture, machine parts, oil system tubes and so on. The standard technical delivery conditions has five types. They are cold finished (hard) (BK), cold finished (soft) (BKW), cold finished and stress-relived (BKS), Annealed (GBK), Normalized (NBK). We’d like to show what’s the same and difference between DIN2391 standard and EN10305-1.
Different delivery conditions have different steel pipes properties. It is form from DIN2391 standard.
Table 1: Chemical composition of steel grades shown on ladle analysis
Chemical composition, as a percentage by mass
The following alloying elements may be added: Nb≤0.03%；Ti≤0.03%；V≤0.05%；Nb+Ti+V：≤0.05%
Table 2: Mechanical properties of tubes at ambient temperature
Different delivery conditions have different steel pipes properties. It is form from EN10305-1 standard.
As both of the standards seamless steel tubes shall have a smooth internal and external surface consistent with the cold working process. As a result the arithmetical mean deviation of the profile. Ra, will be 6.3 um or less. Lower Ra values shall be subject to agreement for quality grade C steel pipes. Note：For Technical Reasons , it is not always possible to obtain a smooth surface on tubes with an internal diameter of less than 15mm.