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Q245R(HIC) is a steel plate designed to resist hydrogen sulfide corrosion. Q245R(R-HIC) is normalized steel to which HIC and SSCC tests have been performed; it is available in cut forms with dimensions of (152+0375+0895). 1. Scope of application: These technical specifications apply to Q245R(HIC) plates with a thickness of 8 mm–150 mm, which are used in acidic environments. Based on the requirements for sulfur and phosphorus content in the steel, these plates are classified into three grades: I, II, and III. 2. Grade specification: Q245R (HIC)-I refers to the steel grade Q245R; the corrosion test involves only hydrogen-induced cracking resistance testing (HIC). The compositional requirements are P≤0.015 and S≤0.003 as determined by melting analysis ； Finished product analysis: P≤0.015, S≤0.004. 3 Technical Requirements 3.1 Chemical Composition Steel grade CSiMnALCa*O*CE** Q245R(HIC) Melting analysis ≤0.20 ≤0.35 0.50–1.00 ≥0.02 0.00 15–0.0030 ≤0.004 ≤0.36 Finished product analysis ≤0.40 0.45–1.05 Table 1 Note: (1) The Ca value is for reference only and is not a requirement for acceptance; the values of Ca and O can be replaced by those from the finished product analysis instead of the melting analysis values ； (2) The formula for calculating the carbon equivalent (CE) is as follows: CE = C + Mn/6 + (Cu + Ni)/15 + (Cr + Mo + V)/5. (3) To improve the properties of steel plates, certain microalloying elements can be added. Table 2 Grade Components: PS I – Melting level: ≤0.015 ≤0.003; Finished product level: ≤0.015 ≤0.004. II – Melting level: ≤0.010 ≤0.002; Finished product level: ≤0.010 ≤0.003. III – Melting level: ≤0.008 ≤0.002; Finished product level: ≤0.008 ≤0.002. 3.2 Smelting method: Electric furnace + secondary refining is used; Ca treatment is applied during the smelting process. The steel should be of essentially fine-grained structure, with an actual grain size of grade 5 or higher. 3.3 Delivery condition: normalized. 3.4 Sample condition: All steel plates shall undergo simulated post-weld heat treatment on their test samples. The recommended temperature for this simulated post-weld heat treatment is 620±10°C, with a holding time of 8 hours. The samples should be removed from the furnace when the temperature exceeds 400°C, and the rate of temperature change should be ≤150°C/h. If the conditions differ from those recommended, the specific parameters for the simulated post-weld heat treatment shall be specified in the contract. 3.5 Mechanical properties 3.5.1 The mechanical properties of the steel plate specimens in a state simulating post-weld heat treatment shall meet the requirements specified in the table below. Table 3 Steel grade, Thickness (mm), ReL MPa, Rm MPa, A% Impact temperature (°C), Impact value J, 180° bending test b=2a, Properties in the thickness direction ψZ (%), Average value, Individual value. Q245R(HIC): 8–16, ≥245, 400–520, ≥25–20; Average value ≥34, Individual value ≥24; d=1.5a: ≥35, ≥25, >16–36; ≥235; >36–60: ≥225; >60–100: ≥205. 390–510: ≥24; d=2a: >100–150, ≥185. 380–500. Note: (1) For steel plates with a thickness of ≥15 mm, properties in the thickness direction are evaluated ； 3.5.2 Brinell hardness: The steel plates shall be tested for Brinell hardness at each rolling pass, with the Brinell hardness value to be ≤ 200 HB. 3.6 Ultrasonic testing: Steel plates shall be subjected to ultrasonic flaw detection one by one, and the standard level for such testing shall be specified in the contract. 3.7 The inspection items, sampling quantity, sampling methods, and testing methods for each batch of steel plates shall comply with the provisions in Table 4. Table 4: Sampling quantities for inspection items (pieces), sampling methods, and testing methods. Chemical analysis*: Melting analysis 1 (per furnace) GB/T20066 GB/T223; Finished product analysis 1 (per rolled sheet): Tensile testing 1 (per rolled sheet) GB/T2975 GB/T228; Bending testing 1 (per rolled sheet) GB/T2975 GB/T232; Properties in the thickness direction 3 (per rolled sheet) GB/T5313 GB/T5313; Grain size 1 (per furnace) YB/T5148-93; Brinell hardness 1 (per rolled sheet) GB/T231; Ultrasonic testing – per sheet, as specified in the contract; HIC testing: as specified in the additional requirements of the contract; Impact testing 3 (per rolled sheet) GB/T2975 GB229; High-temperature tensile testing 1 (per rolled sheet): as specified in the additional requirements GB/T2975 GB/T4338; SSCC testing: as specified in the contract. Note: Items marked with * are optional. Additional requirements (guaranteed only if requested by the user and specified in the contract): 1. Simulated post-weld heat treatment regime; 2. High-temperature tensile testing (to be agreed upon by both parties); 3. Low-temperature impact testing (to be agreed upon by both parties); 4. Test criteria for steel plate resistance to hydrogen-induced cracking (HIC). A. Methods for hydrogen-induced cracking (HIC) testing – either of the following methods may be used: (1) Adhere to the NACE TM0284 standard, using Solution A; the average value of the results for three specimens shall be: CLR≤10% ； CSR≤3% ； CTR≤1%. (2) In accordance with the NACE TM0284 standard, using Solution B, the average value for the three specimens is: CLR≤10% ； CSR≤3% ； CTR≤1.5%. (3) In accordance with GB8650 standard, using Solution A, the average value for the three samples is: CLR≤10% ； CSR≤3% ； CTR≤1.5%. (4) In accordance with GB8650 standard, using Solution B, the average value for the three samples is: CLR≤10% ； CSR≤3% ； CTR≤1.5%. Among them, PH: medium acidity and alkalinity ； CLR: Percentage of crack length ； CSR: Crack sensitivity percentage ； CTR: Percentage of crack thickness. B. Acceptance criteria for HIC testing – HIC testing should be conducted on batches, with each batch consisting of steel plates from the same furnace batch, with the same thickness and under the same heat treatment conditions. When the thickness is not greater than 30 mm, one set of specimens is taken, with the specimen dimensions being plate thickness * 20 mm * 100 mm ； When the thickness is greater than 30 mm, a set of specimens is taken from the midpoint of the thickness, with specimen dimensions of 20 mm * 20 mm * 100 mm.