Procurement specifications for domestic 13MnNiMo54 steel plates

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Specifications for the Procurement of Domestic 13MnNiMo54 Steel Plates WG0601.19-2003 1 Scope These specifications apply to the procurement of 13MnNiMo54 (DIWA353) steel plates for use in domestic boiler drums. The 13MnNiMo54 (DIWA353) steel plates purchased in accordance with these specifications shall meet the requirements specified herein; aside from those, all other aspects shall also comply with the provisions of GB 713-1997. 2 Referenced standards: GB 713-1997 for steel plates used in boilers; JB 4730-1994 for non-destructive testing of pressure vessels; DH-E24-C 13MnNiMo54 (DIWA353) – Specification for weldable steel materials for high-temperature applications. 3 Technical requirements: 3.1 Chemical composition: The results of the melting analysis and final product analysis regarding the chemical composition of the steel plates shall meet the requirements specified in Table 1. Table 1 Chemical composition (%) C Si Mn P S Ni Mo Cr Nb Melting analysis ≤0.15 0.10～0.50 1.00～1.60 ≤0.020 ≤0.010 0.6～1.0 0.20～0.40 0.20～0.40 0.005～0.020 Finished product analysis ≤0.17 0.05～0.56 0.95～1.70 ≤0.025 ≤0.015 0.55～1.05 0.15～0.44 0.15～0.45 0.005～0.025 3.3 Mechanical properties 3.3.1 The room-temperature mechanical properties of the steel plate shall meet the requirements specified in Table 2. 3.3.2 The high-temperature instantaneous tensile properties of the steel plate shall meet the requirements in Table 3, and the test temperature shall be specified in the order contract. 3.3.3 The impact test is calculated as the arithmetic average of 3 specimens; it is permissible for one of the specimens to be below the average value, provided that it is not lower than 85% of the average value. 3.4 Delivery condition The steel plates shall be delivered in the normalized and tempered condition. 3.5 Heat treatment: Normalizing: 890–950 °C; after homogenization, hold at this temperature for 30 minutes, then cool in still air ； Tempering: 620–690 °C; after homogenization, hold at this temperature for at least 30 minutes but not more than 180 minutes, then cool in still air. 3.6 Ultrasonic testing: Steel plates shall be subjected to ultrasonic testing on a sheet-by-sheet basis in accordance with the JB 4730 standard, with the required qualification level being Grade I. 3.7 Surface quality and dimensional tolerances 3.7.1 The surface quality of steel plates shall comply with the provisions of clause 4.5 in GB713. 3.7.2 The allowable deviation for steel plate thickness shall comply with the provisions in Table 4. 　 Table 2 Mechanical properties at room temperature (transverse specimens) Steel plate thickness (mm) Yield strength Rp0.2 (N/mm2) Tensile strength Rm (N/mm2) Elongation A (%) Akv (J) 20°C Cold bending test 180° ≤ 50 ≥ 400 570–740 ≥ 18 ≥ 39 d = 3.5 a > 50 ≤ 100 ≥ 390 > 100 ≤ 125 ≥ 380 > 125 ≤ 150 ≥ 375 Note: The data in this table are taken from the DH-E24-C specifications. Table 3 Minimum yield strength in high-temperature instantaneous tensile tests (transverse specimens)
Steel plate thickness (mm) Minimum yield strength Rp0.2 (N/mm2) in high-temperature instantaneous tensile tests Test temperature (°C)
250 300 320 350 370 400
≤50 373 363 359 353 335 309
＞50≤100 353 343 339 333 321 304
＞100≤125 343 333 329 324 314 299
＞125≤150 333 324 320 314 306 294
Note: The data in this table are taken from the DH-E24-C specifications; the values for 320°C and 370°C were calculated by interpolation. 　Table 4 Allowable deviations for steel plate thickness Nominal thickness in mm Allowable deviation for nominal thickness in mm Allowable deviation between minimum and maximum thicknesses within the same plate in mm Nominal width in mm ≥600～＜2000 ≥2000～＜2500 ≥2500～＜3000 ≥3000～＜3500 ≥3500～＜4000 ＜80 +2.5 –0.3 1.2 1.3 1.4 1.4 1.5 ≥80 ＜150 +2.9 –0.3 1.3 1.4 1.5 1.5 1.6 Note: The data in this table are taken from the DH-E24-C regulations. 　 4 Packaging, Marking and Quality Certificates The packaging, marking and quality certificates of steel plates shall comply with the provisions of GB247. 　 Note: 13MnNiMo54 (DIWA353) can be equivalent to BHW35, 13MnNiCrMoNbg.