SAE/AISI 10B21（IFI-10B21）

ASTM F2282—18 original Table 4/7 and Table 6/9.; Heat analysis mass fraction wt%, not actual measured values per heat. IFI numbers and /A, /B groupings shall be retained separately according to this table and shall not be presumed equivalent to SAE grades of the same number.; /B is not a boron marker within a number.. The residual upper limits in Table 9 are used only for elements without specified alloy ranges and cannot override the alloy Ni/Cr/Mo ranges in Table 7.. Si in Table 6 shall be according to the actual deoxidation method.; Fine grain requirements, grain reports, and 7.2 Al content/S2 agreements shall be verified separately; grain size compliance shall not be proven directly from deoxidation labels.. When B and Ti are not intentionally added, B≤0.0007%, Ti≤0.01%.; For 10B steel, the Table 4 note specifies B 0.0008–0.003% and Ti≥0.01%; do not invent a Ti upper limit where none is listed.. Product analysis deviations in Table 5/8 and the application conditions in 6.4 do not directly relax the default heat limits.. S1: Residual Cr may be relaxed to 0.20 or Mo to 0.06 only if specified in the order.; Reduction of residual limits requires an agreement and shall not be automatically applied to this batch.. S2 explicitly references the Nb/V grain refinement rules of A29/A29M—15 in the original text, which requires order specification and actual measurement of C/elements from the same heat; it shall not be replaced by newer A29 versions.. The SAE/AISI wording in the original website title is only an existing product label.; The grade in the original table for this composition is IFI-10B21; this shall not be used to declare equivalence with SAE/AISI standards.. Deferred condition: AlK deoxidation; Table 4 lists AlK, but the AlK column for boron steel in Table 6 is N/A; Do not borrow Si upper limits from other rows; pending specific agreement.