What is the difference between 15CrMoR(H) and 15CrMoR?

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15CrMoR is a container plate, delivered in the normalized + tempered condition, while 15CrMoR(H) is 15CrMoR steel that has undergone high-temperature treatment and possesses resistance to hydrogen embrittlement. Scope of application: These technical specifications apply to the production and inspection of 15CrMoR(H) steel plates with a thickness of 8–60 mm. 15CrMoR(H) is available in stock or can be ordered in coils of size 152*0375#0895. I. Chemical composition of 15CrMoR(H): Grade – Chemical composition (mass percentage)/%: Ceqb, CSi, Mn, P, S, Cr, Mo, Ni, Cu, As, Sb, Sn. For 15CrMoR(H): 0.12~0.18, 0.15 ~0.40, 0.40~0.70; ≤0.015, ≤0.010; 0.80~1.20, 0.45 ~0.60; ≤0.25, ≤0.20, ≤0.025, ≤0.025, ≤0.025, ≤0.60. a: Actual measured values are provided. b: The calculated value of carbon equivalent shall be indicated in the quality certificate. The method for calculating carbon equivalent is as follows: Ceq = C + Mn/6 + (Cr + Mo + V)/5 + (Ni + Cu)/15. 1.1 The allowable tolerances for finished product analysis shall comply with the provisions of GB/T222. II. Manufacturing method of 15CrMoR(H): 1.2.1 Smelting is carried out using an electric furnace combined with secondary refining, along with vacuum degassing. The steel’s manufacturing and production processes should be specified in the quality certificate. 1.2.2 When rolling slabs produced by continuous casting, the compression ratio must be no less than 3.1.3 Condition of delivery: normalized (accelerated cooling allowed) + tempered; the tempering temperature must be at least 680°C. III. Mechanical properties of 15CrMoR(H): 1.4.1 The mechanical properties of the steel plate shall comply with the requirements specified in Table 2. Table 2: Grade, Thickness (mm), Tensile test (transverse), Impact test (transverse), High-temperature tensile test (transverse), Bend test 180° b=2a, Rm (Mpa), ReL (Mpa), A (%)، Temperature (℃), KV2 (J), Test temperature (℃), Rp02 (Mpa): Not less than, Not less than, Not less than. 15CrMoR (H): 6~60, 450~590, 295, 19, —5, 34, 425, 171.5; d=3a. For temperatures >60~100: 275; for temperatures >100~150: 440~580, 255. a: When yield behavior is not apparent. The yield strength is taken as Rp0.2. b: Conduct high-temperature tensile tests in accordance with the relevant provisions of GB/T4338 and the requirements of the contract; the value of the high-temperature tensile strength shall be included in the quality certificate. 1.4.2 The average impact value KV2 for the three steel plate specimens shall be ≥ 34 J; in a single set of tests, only one specimen is allowed to have a KV2 value of < 34 J, provided that this value is not less than 27 J. 1.4.3 Other requirements shall comply with GB713. 1.5 Surface quality The surface quality of the steel plate shall meet the requirements specified in GB713. 1.6 Ultrasonic testing of steel plates: 100% ultrasonic testing and thickness measurement should be carried out on each steel plate, with the results of the ultrasonic testing meeting the Class I requirements specified in JB/T4730.3.