Main application areas of super austenitic stainless steel
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Since 904L and 254 SMO super austenitic stainless steel have strong resistance to pitting corrosion, crevice corrosion, Cl-stress corrosion and intergranular corrosion, especially to acid ions such as SO4-2 and Cl-, they have good corrosion resistance and can be used in extremely harsh working environments. Therefore, the application of super austenitic stainless steel will become more and more extensive. Currently it is mainly used in the following fields: i. Petroleum and petrochemical equipment, such as bellows in petrochemical equipment ； ii. Pulp and paper bleaching equipment, such as pulp digesters and bleaching equipment ； iii. Power plant flue gas desulfurization device, the main parts used are:: The tower body, flue, door panel, internal parts, spray system, etc. of the absorption tower ； iv. Offshore systems or seawater treatment, such as thin-walled condensation pipes cooled by seawater and seawater desalination equipment in power plants ； v. Desalination industry, such as salt production or desalination equipment ； vi. Heat exchangers, especially heat exchangers in working environments with chloride ions.
Can you tell me more clearly what material super stainless steel is made of?
Chemical composition comparison tablechemical compositionGradechemical compositionCSiMnPSCrNiMoOthers3040.08max0.75max2.00max0.040max0.030max18.00-20.008.00-11.00 304L0.035max0.75max2.00max0.040max0.030max18.00-20.008.00-13.00 304LN0.035max0.75max2.00max0.040max0.030max18.00-20.008.00-11.00 N0.10-0.163160.08max0.75max2.00max0.040max0.030max16.00-18.0011.00-14.002.00-3.00 316L0.035max0.75max2.00max0.040max0.030max16.00-18.0010.00-15.002.00-3.00 316N0.08max0.75max2.00max0.040max0.030max16.00-18.0011.00-14.002.00-3.00N0.10-0.1 6316LN0.035max0.75max2.00max0.040max0.030max16.00-18.0011.00-14.002.00-3.00N0.10-0 .16316Ti0.08max0.75max2.00max0.040max0.030max16.00-18.0010.00-14.002.00-3.00Ti5(C +N)-0.70316H0.04-0.100.75max2.00max0.040max0.030max16.00-18.0011.00-14.002.00-3.00 3210.08max0.75max2.00max0.040max0.030max17.00-20.009.00-13.00 Ti>5xC max0.60%3170.08max0.75max2.00max0.040max0.030max18.00-20.0011.00-14.003.00-4.00 317L0.035max0.75max2.00max0.040max0.030max18.00-20.0011.00-15.003.00-4.00 3470.08max0.75max2.00max0.040max0.030max17.00-20.009.00-13.00 Co+Ta>10xC,max1.00%N08904(904L)0.02max1.00max2.00max0.040max0.030max19.00-23.0023.00-28.004.00-5.00N≦0.10,Cu 1.0-2.0S318030.03max1.00max2.00max0.030max0.020max21.00-23.004.50-6.502.50-3.50N0.08-0.20S322050.03max1.00max2.00m ax0.030max0.020max22.00-23.004.50-6.503.00-3.50N0.14-0.204050.08max0.75max1.00max0.040max0.030max11.50-13.500.50max Al0.10-0.304100.15max0.75max1.00max0.040max0.030max11.50-13.500.50max 4300.12max0.75max1.00max0.040max0.030max16.00-18.000.50max 430Ti0.10max1.00max1.00max0.040max0.030max16.00-19.500.75max Ti5xC min;0.75max 304H0.04-0.100.75max2.00max0.040max0.030max18.00-20.008.00-11.00 321H0.04-0.100.75max2.00max0.040max0.030max17.00-20.009.00-13.00 Ti>5xC,max0.60%347H0.04-0.100.75max2.00max0.040max0.030max17.00-20.009.00-13.00 Co+Ta>8xC,max1.00%310S0.08max0.75max2.00max0.045max0.030max24.00-26.0019.00-22.000.75max 310H0.10max1.00max2.00max0.045max0.030max24.00-26.0019.00-22.00
I would like to ask the poster, what are the differences in the manufacturing process or composition between super austenitic stainless steel and austenitic stainless steel? I can learn from you.* .
In terms of application, attention should be paid to its various performances: Hardness, tensile strength, corrosion resistance, etc. The specific application depends on whether the material can meet the application environment. Every material has its own characteristics. In a certain place, only it works. If you move to another place, it would be hard to tell.
David W introduces three common stainless steel smelting processes. Currently, there are three methods of stainless steel smelting in the world, namely one-step method, two-step method and three-step method. one step method: That is, the electric furnace smelts stainless steel in one step. Since the one-step method has strict requirements on raw materials (stainless steel scrap, low carbon ferrochrome and metallic chromium need to be returned), the consumption of raw materials and energy media in production is high, the cost is high, the smelting cycle is long, the productivity is low, the product variety is small, the quality is poor, the life of the furnace lining is short, and the consumption of refractory materials is high, so this method is rarely used to produce stainless steel. Two-step method In 1965 and 1968, VOD and AOD refining devices were produced one after another, and they played a decisive role in changing the stainless steel production process. The former is decarburization by vacuum blowing oxygen, and the latter is decarburization by diluting gas with argon and nitrogen. Coupling either of these two refining facilities with an electric furnace creates a two-step stainless steel production process. The two-step steelmaking process of electric furnace and VOD is more suitable for the stainless steel production of small-scale and multi-variety compatible plants. Using the two-step steelmaking process of electric furnace and AOD to produce stainless steel has the following advantages:: 1. The AOD production process has low requirements on raw materials. The C content of electric furnace steel can reach about 2%. Therefore, cheap high-carbon FeCr and 20% stainless steel scrap can be used as raw materials, which reduces operating costs. 2. The AOD method can remove 0.08% of the carbon in the molten steel in one step. If the smelting time is extended and the amount of Ar is increased, the carbon in the molten steel can be further removed to less than 0.03%, in addition to ultra-low carbon. Except for ultra-low nitrogen stainless steel, 95% of varieties can be produced. 3 The stainless steel production cycle is shorter than VOD and has better flexibility. 4. The total investment in production system equipment is more expensive than VOD, but less than the three-step method. 5. The AOD furnace produces steel in one step, with fewer personnel and less equipment, so the overall cost is lower. 6. AOD can use primary molten steel containing less than 1.5% C, so it can use low-priced high-carbon FeCr, FeNi40 and 35% carbon steel scrap for batching, and the raw material cost is low. The disadvantage is: 1. Furnace lining has short service life ； 2. Reducing ferrosilicon consumes a lot of money ； 3. It is currently not possible to produce ultra-low C, ultra-low nitrogen, and stainless steel, and the gas content in the steel is high. ； 4. Large consumption of argon gas. Currently, 88% of stainless steel in the world is produced using the two-step method, of which 76% is produced through AOD furnaces. Therefore, David W is more suitable for large-scale stainless steel professional factories. three step method: That is, electric furnace + double blowing converter + VOD three-step smelting of stainless steel. Its characteristic is that the electric furnace, as a melting equipment, is only responsible for providing semi-finished molten steel containing Cr and Ni to the converter. The main task of the double-blown converter is to blow oxygen to quickly decarburize to achieve the purpose of maximizing Cr recovery. VOD vacuum oxygen blowing is responsible for further decarburization, degassing and compositional fine-tuning. The three-step method is more suitable for areas where argon supply is in short supply, and is used by professional factories that use molten iron with higher carbon content as raw material and produce a larger proportion of low-C and low-N stainless steel.
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