25MNTIBRE

Table 1 of GB/T3077-2015 is for heat analysis, and Table 2 is for P/S and residual element requirements.. ; The final note of Table 1 allows all grades to be ordered as high-grade/extra-high-grade quality steel, with A/E added after the grade respectively.; Quality level for this record: quality steel.. ; For steel used in hot-pressure working, Cu≤0.20%.; The general Cu upper limit cannot be applied to this purpose.. ; The alloying ranges specified in Table 1 shall take priority.; Unspecified Cr/Ni/Mo shall follow the residual upper limits in Table 2; residual upper limits shall not be superimposed on alloying elements.. ; Sn/Sb/As must be analyzed and recorded in the quality certificate, with limits by agreement when required.; No unified numerical limits shall be fabricated here. ; Product analysis deviations shall be used separately according to GB/T222 and shall not directly expand the heat range. ; Mechanical properties require consideration of specimen size and recommended heat-treatment/delivery conditions. This composition review does not establish that mechanical properties have been verified.. ; Table 1 Note a: Rare earths are added based on a calculated amount of 0.05%; product analysis results are for reference; The addition amount of 0.05% shall not be written as a guaranteed composition..

GB/T 3077—1999, Table 1: ladle analysis, mass fraction wt%; this record follows the actual 1999 edition, not the 2015 edition. Grades without suffix A in the table are ordered as quality steel. Table 2 P/S/Cu and residual Mo follow the applicable quality grade; residual Cr/Ni/Mo limits do not override alloy contents specified in Table 1. The chemical composition also applies to ingots, billets and their products; bar scope, mechanical properties and surface-quality requirements do not by themselves guarantee suitability as cold-heading wire. If the processing use is not specified in the contract, machining applies; for hot-pressure processing, Cu≤0.20%, select the applicable condition. Under 6.1.1.2, residual W/V/Ti are analyzed and reported on the certificate; no common limit is stated for unlisted elements, so do not enter zero; Table 1 alloy ranges for W/V/Ti remain applicable. Table 1 Note 2: upgrading to A/E quality or specifying other chemistry by agreement requires a separate order check; do not merge grades or rewrite this row’s C range. Note 4: rare earth 0.05% is a calculated addition; product analysis is for reference, not a guaranteed range. Product-analysis tolerances for steel/billets are separately checked against cited GB/T 222—1984 and do not automatically relax ladle limits.