The use of alloy 12X18H10T
Alloy 12X18H10T is used in welded structures working in contact with nitric acid and other oxidizing media; in some organic acids of medium concentration, organic solvents, atmospheric conditions, etc. They make capacitive, heat exchange and other equipment.
For the manufacture of welded structures in cryogenic technology at temperatures up to - 269 ° C.
Steel is smelted in electric arc furnaces.
The chemical composition of the alloy 12X18H10T
| C | Cr | Fe | Mn | Ni | P | S | Si | Ti |
|---|---|---|---|---|---|---|---|---|
| ≤0,08 | 17-19,0 | Осн. | ≤2,0 | 9-11,0 | ≤0,035 | ≤0,020 | ≤0,8 | 5·С-0,8 |
Corrosion resistance of alloy 12X18H10T
According to GOST 7350-77, GOST 5582-84, GOST 4986-78, GOST 5945-75, GOST 18143-72, GOST 9940-81 and GOST 9941-81 steel 12X18H10T and according to GOST 7350-77, GOST 5945-75, GOST 18143-72 steel 12X18H9T must be resistant to intergranular corrosion when tested according to the methods AM and AMU GOST 6032-89 with a duration of exposure in the control solution of 24 and 8 hours, respectively. The tests are carried out after provoking heating at 650 ° C for 1 hour.
During continuous operation, they become resistant to oxidation in air and in the atmosphere of fuel combustion products at temperatures up to 900 ° C and during operation in heat exchange conditions up to 800 ° C.
Steel 12Kh18N10T and 12Kh18N9T have a high heat resistance at 600-800 ° C.
Technological parameters 12X18H10T
Steel 12Kh18N10T and 12Kh18N9T have good adaptability to hot plastic deformation. However, during hot processing, it is necessary to take into account the specific chemical composition of this heat, bearing in mind the content of 8-ferrite. Special precautions should be taken when cast metal is deformed. In order to avoid the formation of irreparable defects - flaws, it is recommended that 12Kh18N10T and 12Kh18N9T steel ingots with a content of 20% 8-ferrite and more be heated no higher than 1240-1250 ° C, with a content of 16-19% not higher than 1255 ° C and with a content of up to 16% - up to 1270 ° C. The temperature range of the pressure treatment of the deformed metal is 1180-850 ° C. The speed of heating and cooling is not limited.
When cold, both steels allow high degrees of plastic deformation.
In order to relieve stresses and improve the durability of welded joints, in addition to hardening, welded structures are subjected to stabilizing annealing at 850-900 ° С.
Alloy welding 12X18H10T
Steel 12X18H10T and 12X18H9T are well welded by all types of manual and automatic welding. For conventional automatic submerged arc welding AN-26, AN-18 and argon-arc welding using wire Sv-08X19N10B, Sv-04X22N10BT, Sv-05X20N9FBS and Sv-06Kh21N7BT, and for manual electrodes of the EA-1F2 type of the GL-2, TsL-2B2, EA-606/11 grades with wire Sv-05X19N9FZS2, Sv-08Kh19N9F2S2 and Sv-05X19N9FZS2. The wire Sv-08X20H9S2BTY is recommended for manual automatic welding in protective gas.
For manual electric arc welding, the TsL-11 and TsL-9 electrodes with the material of the electrode rod, respectively, Sv-07X19N10B and Sv-07X25N13 can also be used. Both types of electrode provide resistance of the weld metal against intergranular corrosion when tested according to the methods AM and AMU GOST 6032-89 without provoking heating. The welded joints obtained using the TsL-11 and TsL-9 electrodes have the following mechanical properties (at least), respectively: σb = 550 and 600 N / mm2, δ = 22 and 25 %, KCU= 80 and 70 J / cm2.
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