Steel Tube Handbook - 2018

6 Steel quality groups according to the chemical composition Steel classifications in the main quality groups NON-ALLOY STEEL NON-ALLOY QUALITY STEEL NON-ALLOY SPECIAL STEEL Contents of the elements does not reach the values listed in the table > > > For general requirements: - Impact energy - Grain size - Formability + Intended for refining and surface har- dening etc.. Guaranteed minimum absorbed energy. Low content of non-metallic inclusions STAINLESS STEEL BASIC PROPERTIES Content of C. 1.2% max Content of Cr 10.5% min Content of Ni is less than 2.5% or higher than 2.5% Corrosion resistant steel Creep resistant steel Heat resistant steel OTHER ALLOY STEEL ALLOY QUALITY STEEL ALLOY SPECIAL STEEL This is not stainless steel, con- tent of at least one element re- aches values in the table on the previous page fine grained structural steel steel for rails and girders steel for heavy use alloy steel by Cu steel for electrical engineering + structural steel for pressure vessels for roller bearings tool steel high-speed steel special physical properties Steel classifications according to STN EN 10020 Table 1 Regulation EN ECISS IC10 establishes additional symbols for steel (Groups 1 and 2). These symbols are placed at the end of the steel mark (e.g. S 275 J0). Additional symbols for steel products are given in Tables 1, 2, 3 and from the pre- vious symbols must be separated by a plus sign (+) - e.g. S 275 J0 + A. Symbols for steel tubes G - other characteristics (if necessary 1 to 2 digits) H - hollow profile or for higher temperatures steel accor- ding to the type of steel (S, P) L - steel for low temperature R - steel for common temperature (room temperature) M - thermomechanically rolled N - normalized or normalized rolled Q - heat treated T - steel for tubes EN 10027-2 contains the numerical system marking. The first number is 1 - steel, followed by two digits of ste- el group and the serial number of steel ( 1.0402, 1.7218, 1.7386, 1.3339 ). See Tab. No. 57 on page 119 Indicative comparison of old and new labeling of the Eu- ropean basic structural steel (steel group 1) In addition to introducing the letters for the field of applica- tion of tubes (S, E, P, L, etc.) two changes occurred: 1 Instead of the minimum value of tensile strength Rm is now in the steel marking listed value of the upper yield strength ReH 2 Old units kp/mm2 were replaced with new units N/mm2 ( MPa ). Example: Old steel markings: Type of steel St35, St35.8, St37.0, St37.4, ČSN 11353, etc.. have values in the old units: Re min. = 23.5 kp/mm2, Rm min. = 35 kp/mm 2 . New steel markings: Identical resp. similar to steel 235JRH S, E 235, P 235TR1 etc. have similar mechanical properties in new units: Re min. = 235 MPa , Rm min. = 340-360 MPa.