Steel 08KH18N12B (ЭИ402)
|Designation GOST Cyrillic||08Х18Н12Б|
|Designation GOST Latin||08X18H12B|
|By chemical elements||08Cr18Н12Nb|
|Designation GOST Cyrillic||ЭИ402|
|Designation GOST Latin||EI402|
|By chemical elements||-|
08KH18N12B steel is used: for the manufacture of various parts and structures, welded by spot welding; parts of high viscosity in the apparatus, refrigeration machines, General and aviation engineering, working at temperatures down to -253 °C; in various parts, operating at temperatures from -196 °C to +600 °C in corrosive environments; welded equipment operating in environments of increased aggressiveness (the solutions of nitric, acetic acids, alkaline solutions and salts); structures to be welded by spot welding; the various parts and equipment of oil, neftepererabativaushiy and chemical industries; welded structures and joints operating in radioactive environments.
Steel corrosion resistant.
Stabilized chromium-Nickel steel of austenitic class.
08KH18N12B steel has higher resistance to work in nitric acid and to pitting than steel 12X18H10T.
|Test methods. Packing. Marking||В09||GOST 11878-66|
|Sheets and strips||В33||GOST 5582-75, GOST 7350-77, TU 14-1-2186-77|
|Classification, nomenclature and General rules||В30||GOST 5632-72|
|Bars and shapes||В32||GOST 5949-75, TU 14-11-245-88|
|Steel pipes and fittings to them||В62||GOST 9940-81, GOST 9941-81, TU 14-3-1654-89|
|Blanks. Of the workpiece. Slabs||В31||OST 3-1686-90, TU 14-1-565-84|
|Welding and cutting metals. Soldering, riveting||В05||OST 95 10441-2002|
|Thermal and thermochemical treatment of metals||В04||STP 26.260.484-2004|
According to GOST 5632-72 the content of Nb% = 10С% - 1,1%.
According to TU 14-1-2186-77 the content of Nb% = 8C% is 1.2%.
|Section, mm||sT|s0,2, MPa||σU, MPa||d5, %||y, %|
|Hot rolled sheet (of 1.5-3.9 mm) and cold rolled (0,7-3,9 mm) steel according to GOST 5582-75. Quenching in water or air from 1050-1080 °C|
|Hot rolled sheet (4,0-50,0 mm) and cold rolled (4,0-5,0 mm) steel according to GOST 7350-77. Quenching in water or in air, 1000-1100 °C|
|Bars hot rolled and forged according to GOST 5949-75. Quenching in air, oil or water with 1020-1100 °C|
|Bars hot rolled and forged at STP 26.260.484-2004. Quenching in water or air from 1050-1100 °C|
|Bars hot rolled and forged at STP 26.260.484-2004. Stabilizing annealing at 870-900 °C, air cooling or Stepwise treatment regime: heating to 1050-1100 °C; the holding time at the heating for products with wall thickness up to 10 mm - 30 min, over 10 mm - 20 min + 1 min per 1 mm of maximum thickness; cooling as fast as possible to 870-900°C; holding at 870-900 °C for 2-3 hours; cooling with the furnace to 300 °C (speed of 50-100 °C/h), then in the air|
|Tubes in the delivery condition|
Description mechanical marks
|sT|s0,2||Yield strength or limit of proportionality with a tolerance for residual deformation of 0.2%|
|σU||Limit short-term strength|
|d5||Elongation after rupture|
|y||The relative narrowing|
|Temperature||Е, HPa||r, kg/m3||R, Mr. · m|
A description of the physical symbols
|Е||The normal elasticity modulus|
|l||Coefficient of thermal conductivity|
|R||UD. the resistivity|
|Features of heat treatment||Depending on assignment, working conditions, corrosive environment the product is subjected to: a) hardening (austenization); b) stabilizing annealing; C) annealing for stress relieving; d) a stepwise processing. The product is quenched in order to: a) prevent the tendency to intergranular corrosion (products can operate in temperatures up to 350 °C); b) to increase resistance against General corrosion; C) to eliminate the revealed tendency to intergranular corrosion; g) to prevent the tendency to stab corrosion (welded work product in solutions of nitric acid); d) to eliminate residual stress (products simple configuration); e) to increase the plasticity of the material. The quenching products should be carried out on mode: heating to 1050-1100 °C, items material thickness up to 10 mm cooling on air, more than 10 mm in water. Welded parts of complex configuration in order to avoid the leash is to be cooled in the air. The holding time at the heating for hardening to products with a wall thickness up to 10 mm - 30 min, over 10 mm - 20 min + 1 min per 1 mm maximum thickness. In the hardening of products, intended for operation in nitric acid, the heating temperature for hardening must be kept at the upper limit (exposure at the same weldment should be not less than 1 hour). Stabilizing annealing is applied to: a) prevent the tendency to intergranular corrosion (products work at temperatures above 350 °C); b) stress relief; C) the elimination of discovered tendency to intergranular corrosion, if for any reason hardening is inappropriate. A stabilizing annealing, for example for products and welded joints of steels in which the ratio of titanium to carbon 5 or more of niobium to carbon greater than 8. Stabilizing annealing to prevent the tendency to intergranular corrosion products, operating at temperatures over 350 °C can be subjected to steel containing not more than 0.08 % of carbon. Stabilising annealing should be carried out according to the mode: heating up to 870-900 °C, exposure time of 2-3 h, cooling in air. During heat treatment of large welded products are permitted to carry out local stabilizing annealing of closing seams in the same mode, with all welded components shall be subjected to a stabilizing annealing before welding. In the case of local stabilizing annealing is necessary to ensure both uniform heating and cooling across the length of the weld and adjacent base metal zones for a width equal to two or three widths of a seam, but not more than 200 mm. Manual heating method is invalid. For a more complete removal of residual stresses, the annealing products of stabilized chromium-Nickel steels is performed according to the mode: heating up to 870-900 °C; exposure of 2-3 h, cooling with the furnace to 300 °C (cooling rate of 50-100 °C/h), then by air. The annealing is carried out for products and welded joints of steel, from which the ratio of titanium to carbon 5 or more of niobium to carbon greater than 8. Step processing is to: a) relieve residual stresses and prevent the tendency to intergranular corrosion; b) to prevent the tendency to intergranular corrosion of welded joints of complex configuration with sharp transitions in thickness; C) products with the tendency to intergranular corrosion, remove which other method (annealing or stabilizing annealing) is inappropriate. Step treatment should be carried out according to mode: heating to 1050-1100 °C; the holding time at the heating for hardening to products with a wall thickness up to 10 mm - 30 min, over 10 mm - 20 min + 1 min per 1 mm of maximum thickness; cooling as fast as possible to 870-900°C; holding at 870-900 °C for 2-3 hours; cooling with the furnace to 300 °C (speed of 50-100 °C/h), then by air. To expedite the process, step-by-step treatment is recommended in two in two furnaces heated to different temperatures. When transferring from one furnace to another, the temperature of the products should not be below 900 °C. Speed of processing permitted for products and welded joints of steel, from which the ratio of titanium to carbon 5 or more of niobium to carbon greater than 8.|