ISO 6306:2020 pdf download Chemical analysis of steel — Order of listing elements in steel standards
1 Scope
This document specifies an order for listing elements within the chemical composition of steels andmost other iron-based alloys, excluding foundry irons.
NOTE This document has been developed and is used by ISo/TC 17/SC 4, but can also be used by otherISO/TC 17 subcommittees.
2Normative references
There are no normative references in this document.
3Terms and definitions
No terms and definitions are listed in this document.
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4Order of listing elements in steel standards
The elements are divided into three groups.These groups have no real technical significance, but theyare considered to provide the easiest means of readily remembering the following order.
Group 1 includes five elements that are regarded as the most important in all types of steel (C,Si, Mn,Pand S)J.Also included in this group are the four elements of the next greatest importance in alloy steelsand stainless steels (Cr,Ni， Mo and N).
Group 2 is reserved for any element not assigned in group 1 or group 3. When more than one suchelement is determined, they should be arranged in alphabetical order of their chemical symbols.Usuallythese are the following 12 elements: Al, As, B, Co, Cu, Nb, Pb, Sn, Ti, V,W and Zr, which are commonlydetermined in a wide variety of commercial steels.
Group 3 is reserved for hydrogen H.
The recommended order thus becomes:-C, Si, Mn, P, S,Cr, Ni, Mo, N;
other elements determined, in alphabetical order of their chemical symbols, such as Al, As,B,Co Cu,Nb, Pb, Sn, Ti, V, W,Zr;
一H.
With the exception of hydrogen, elements should be reported in % mass fraction irrespective of thecontent. Hydrogen should be reported in mg/kg mass fraction.
Maximum values in the tables for the chemical composition shall be mentioned per se without max. or smaller equal symbol. Therefore, a footnote shall be added in the tables which gives the following explanation: “Maximum values unless indicated otherwise.” When writing the content in % mass fraction of each element into the table of chemical composition, the number of digits shown in Table 1 should be mentioned.ISO 6306:2020 pdf download