09MnNiDR 〓 〓 〓 〓 Introduction and Applications 09MnNiDR cryogenic pressure vessel steel. "D" is the first letter of the alphabet low "R" is the first letter of the alphabet plate ultrasonic inspection standards implementation capacity by GB / T2970 or JB / T4730.3, inspection standards and quality level specified in the contract. Steel surface does not allow the presence of cracks, bubbles, inclusions, such as folding and the use of harmful defects. There should be tiered plate. Steel batch inspection, each batch of steel from the same brand, the same heat, the same thickness, composed of the same heat treatment system, batch weighing not more than 30T, 30T steel sheet weighing more than approved by Zhang group. According to customer requirements, can be thicker than 16mm of steel sheets by heat treatment mechanical properties test. Mechanical properties of the sample position according to the provisions GB / T2975, the thickness of more than 40mm of steel, the impact should be located in the axis of the specimen thickness of a quarter. Steel packaging, marking and quality certificate shall comply with the provisions of GB / T247's. 〓 〓 〓 〓 delivery status 09MnNiDR normalizing or normalizing + tempering quenching and tempering temperature impact -70 degrees. 〓 〓 〓 〓 Wugang 09MnNiDR origin, Xiangtan Steel, the new steel, Wuhan Iron and Steel, heavy steel, Nanjing, Jinan Iron and Steel 〓 〓 〓 〓 chemical composition Chemical composition (mass fraction) Wt% C Si Mn Ni V Nb Alt PS no more than 09MnNiDR ≤0.12 0.15 ~ 0.50 1.20 ~ 1.60 0.3 ~ 0.8 -.. ≤0.04 ≥0.020 0.020 0.008 Spot implementation of national standards content in the range of the futures contract in the above table can be designed to control the content of chemical elements demand 〓 〓 〓 〓 grade mechanical properties edit post Cargo state plate thickness / mm tensile test impact test bending test tensile strength Rm, MPa yield strength Elongation A /% Temperature / ℃ V-type impact energy of not less than 180 ° is not less than b = 2a 09MnNiDR normalized or normalized Tempering 6 ~ 16 440 ~ 570 300 23 -70 34 d = 2a> 16 ~ 36 430 ~ 560 280> 36 ~ 60 430 ~ 560 270> 60 ~ 120 420 ~ 550 260 〓 〓 Wugang 09MnNiDR and German imports 13MnNi6- 3 tensile, impact test results comparing the state of the sample thickness 〓 〓 grade yield strength σa direction tensile strength σb δ5% Ψ% -70 ℃ AKV transverse (J) 09MnNiDR 24 normalizing transverse 380-410520-530 31-3273- 75 282 286 288 13MnNi6-3 24 normalizing transverse 390-385 575-58029-31 75-7419516661 These results suggest that the production of low-temperature Wugang pressure vessel steel with good toughness and low temperature impact toughness, physical quality over or close to the same level of physical quality of foreign steel companies. Compare 〓 〓 〓 〓 level of -70 ℃ 09MnNiDR steel has been included GB150-1998 "steel pressure vessel." EN10028-4 in 0.5Ni -60 ℃ low temperature steel plate a maximum thickness of 50mm, the United States, -70 ℃ low temperature steel for 2.3Ni grade steel, while its low-temperature impact energy index is far below our 09MnNiDR plate. Mm total thickness of steel inclusions% Al2O3% SiO2% MnO% FeO% 50 SA516Gr70 0.0015 0.0005 0.0001 0.0002 0.0001 45 15MnNbR 0.0013 0.0003 0.0002 0.0001 0.0001 14 SA662GrC 0.0016 0.0004 0.0001 0.0001 0.0002 70 16MnDR 0.0015 0.0004 0.0002 0.0001 0.0001 60 09MnNiDR 0.0013 0.0003 0.0001 0.0002 0.0001 09MnNiDR steel for a small amount of ferrite and pearlite low-temperature steel. Due to low carbon content, a low-alloy structural steel, Mn, Ni its main alloys. Mn mainly through solid solution strengthening to increase the strength of steel, and Ni can improve the low temperature toughness of the ferrite, and has significantly reduced the effect of cold brittle transition temperature. Carbon equivalent ≤0.44, hardening tendency of small, difficult to form cold cracks, welds with good ductility and toughness, usually without preheating. When the thickness exceeds a certain thickness, the joint rigid restraint large or high carbon equivalent, should be considered to warm up. But preheating temperature is not too high, otherwise it would be heat-affected zone grain growth and grain boundaries oxides. So, when welding control layer between the welding heat and temperature, but also eliminate the stress of heat treatment after welding. Pure Ni solid solution in the steel elements, with significantly reduced cold brittle transition temperature effect. Ni and Fe in the form of miscible and exist in a 7-iron phase, through its adsorption in the grain refinement of ferrite grains, to improve the impact toughness of the steel. Ni is an austenite but expanded element, lowering the austenite transformation temperature, which affects the rate of diffusion of the carbon and alloying elements, to prevent the austenite to pearlite transformation, reducing the critical cooling rate of the steel, quenched steel can be improved permeability, easy to make steel bainite and martensite. Therefore, appropriate control Ni content to keep it pearlite is key to improving the toughness of a single ferrite. Wugang cryogenic pressure vessels used in the production process of steel sheet, according to the requirements of different standards and technical agreements as well as strength and toughness of the needs of different types of steel, developed a strict internal control components, add (or not add) different micro-alloying elements the steel sheet to obtain grain refinement and precipitation strengthening comprehensive strengthening effect, so that a good fit and low temperature impact toughness tough. Wugang cryogenic pressure vessels at the same time special attention to the actual production of the chemical composition of the steel plate in the stable, so as to obtain a reasonable strength, toughness reserves steel foundation.