08Ni3DR(SA203E) steel plate for low-temperature pressure vessels

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The development of modern science and technology has promoted the production and use of liquefied gases. In particular, the widespread application of petroleum-based and air separation oxygen production equipment, as well as synthetic ammonia production, has led to an increasing demand for low-temperature steel containing 3.5% Ni, with a minimum operating temperature of –101°C – namely 08Ni3DR (SA203E) (also known as 3.5Ni). Key equipment such as the cracking and separation unit in the 480,000-ton/year ethylene expansion project at Daqing Petrochemical Complex, the methanol washing tower, H2S concentration tower, and CO2 tower used in the 300,000-ton/year synthetic ammonia production facility built by Sinopec’s Nanhua Chemicals Division, the methanol mist catcher designed for Shanxi Fertilizer Factory, and the CO2 tower in the 300,000-ton/year synthetic ammonia production equipment manufactured by Jihua Group Machinery Co., Ltd., all require SA203E steel plates. At present, almost all of this type of steel plate is imported from the United States, Europe, and Japan; it is expensive and has long delivery times. In order to make 08Ni3DR(SA203E) steel plates available domestically, Wugang Company began developing such plates in 2006. The mechanical properties of both the base metal and the welded joints of these plates were evaluated by a reputable testing institution—the Hefei General Machinery Research Institute. The performance of these plates proved to be excellent. In June 2008, they passed the evaluation organized by the National Boiler and Pressure Vessel Standards Technical Committee, and on December 15, 2010, they passed an additional technical evaluation conducted by the same committee. The thickness of the steel plates evaluated was up to 100 mm, with a phosphorus content of 0.007%. ； Sulfur content is very low (0.003%), the steel has excellent metallurgical quality; the low-temperature impact energy of the steel plate at -101°C is above 150 J. It meets technical specifications that are higher than those of American ASME SA203E. 1. Scope: This standard applies to steel plates with a thickness of 8 mm–100 mm. 2. Referenced documents: Omitted here. 3. The suffixes D and R listed in this standard refer to the initial letters of the pinyin for \"low temperature\" and \"container\" respectively, in the context of low-temperature pressure vessels. 4. The dimensions, shape, and allowable tolerances of the steel plates shall comply with the provisions of GB/T 709; the thickness tolerances shall meet the requirements specified in Class B of GB/T 709, or Class C as required by the purchaser. 5. The allowable tolerances for the chemical composition of the finished steel plates shall comply with the provisions of GB/T 222. However, the allowable upper deviation for the P content should be 0.003%, while the allowable upper deviation for the S content should be 0.002%. 5: Smelting method: Smelting is carried out using an electric furnace along with secondary refining outside the furnace and vacuum degassing; the resulting steel should be fine-grained killed steel. 6. Delivery condition: 1. The steel plates are delivered in a state of normalizing (with allowed accelerated cooling) followed by tempering, or in a state of offline quenching followed by tempering; the tempering temperature shall be no less than 620°C. For steel plates with a thickness not exceeding 25 mm, they may be delivered in a normalized state. 2. The Charpy (V-notch) low-temperature impact energy is calculated as the arithmetic average of 3 specimens; it is permitted for one of the specimens to have a value that is lower than the value specified in Table 2, but this value must still be no less than 70% of the specified value. 7. Ultrasonic testing shall be carried out on the steel plates in accordance with JB/T4730; the acceptable grade for ultrasonic testing is Grade 1