SM520B

Actually based on JIS G3106:2020 Clause 5 Table 2 and Normative Annex JA Table JA.1; composition is heat analysis mass fraction wt%; The original text of the 2024 edition has not yet been verified; compliance of the new edition shall not be confirmed based on this. Applicable to hot-rolled steel for welded structures; Check the thickness of plates, strips, sections and flat bars separately against Table 1; hot-extruded sections are also subject to Annex JC. This does not constitute a supply guarantee for cold-heading wire.. Please select the thickness and whether it belongs to thick steel plates agreed upon by both the supplier and the purchaser; Ordinary thickness Table 2 and agreed thick plate Table JA.1 shall not be used interchangeably. Dashes and unlisted elements in the table do not mean zero content; additions may be made where necessary.; Do not calculate the complete carbon equivalent based on missing items. For SM400A, evaluate Mn against Mn≥2.5×C using measured C from the same heat; do not use the C upper limit to invent a fixed Mn lower limit.. The upper limit of Mn for agreed thick plates in Annex JA must be stipulated by both the supplier and the purchaser; For SM400B, only Mn≥0.60% is additionally provided; the 1.50% upper limit for ordinary thickness shall not be used. Ceq in this standard uses the JIS-specific formula; The IIW/CEV, Pcm, and CET tools on the website are for engineering estimation within the noted applicable range only, and do not replace the heat treatment, thickness, and agreement requirements of this standard. The JSA corrigendum dated 2021-5 changed explanatory text; it did not change the chemical limits in Table 2 or Table JA.1 reviewed in this batch..

Q/BQB 130—2003 is a standard for slabs produced by initial rolling for subsequent rerolling. The finished plate thickness in Table 3 means the plate thickness after rerolling the slab, not slab thickness or wire diameter. Table 3 gives ladle analysis in mass fraction wt%; C = capped steel, A = aluminium-killed steel, G = aluminium-silicon-killed steel, K = silicon-killed steel. Read the applicable condition row; unlisted elements are not assumed to be zero. Note 3 to Table 3 requires slabs for thick plate (finished thickness ≥15 mm) to use G aluminium-silicon-killed steel; buyer and supplier must verify applicability of rows involving other deoxidation methods. Product-analysis tolerances for killed steel are separately governed by GB/T 222 and must not be mixed with Table 3 ladle-analysis values.