Steel 12Х18Н12Т (Х18Н12Т)
Designation
Description
12Х18Н12Т steel is used: for the manufacture of sheet and rolled; pipes and various parts operating at temperatures from -196 °C to +600 °C in the aggressive environments of billets intended for the manufacture of seamless cold, warm, hot-wrought, including hot-pressed and hot-pressed reduced pipes for steam boilers and pipelines, installations with high and supercritical steam parameters; 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; connections of equipment installed in radioactive environments and in contact with aggressive environment; hull structures of ships, vessels, marine equipment products and shipyards (pipelines, fittings, fairings, various instruments).
Note
Low steel, corrosion-resistant, heatresistant and heat-proof.
Stabilized chromium-Nickel steel of austenitic class.
Magnetic permeability μ ≤ 1,01 GS/E. Steel usually contains the α-phase. Unfavorable balance of alloying elements and carbon magnetic permeability can be up to 1.50 GS/E.
Heat treatment - austenization or stabilization, the hot pressure treatment and flexible at temperatures primenyaemyh for hot deformation do not alter the permeability, and hardening higher than 5−10% at room or lower temperatures significantly increases it.
12Х18Н12Т steel has a lower content of ferritic phase than steel 12X18H10T.
The recommended maximum operating temperature for a long time +800 °C, for a very long time +600 °C.
Temperature intense scaling in air +850 °C.
Steel has low friction properties and prone to scuffing, so is not usually used in friction pairs. To improve the antifriction properties of the nitriding is performed under special conditions with the use of ammonium chloride to remove the oxide film.
Standards
Chemical composition
According to GOST 5632-72, TU 14-1-1529-2003 and RD 9257-76, the content of Ti% = 5C% is 0.7%. For aircraft components, the Mo content is ≤ 0.30%.
According to TU 14-1-1529-2003, the mass fraction of the residual elements: tungsten, vanadium, molybdenum must meet the requirements of GOST 5632. For steel 12Х18Н12Т-Ш the sulfur content should be ≤ 0,15% phosphorus content ≤ 0,30%.
According to TU 14-3-460-2003 the content of Ti% = 5 · (С-0,2)% - 0,7%. Mass fraction of residual elements: tungsten, vanadium, molybdenum must meet the requirements of GOST 5632.
According to TU 14-158-137-2003 the content of Ti% = 5С% - 0,7%. It is permissible to introduce cerium and other rare-earth metals according to the calculation by 0.2-0.3%, which are not determined by chemical analysis.
According to TU 14-3R-55-2001, a technological addition of rare earth elements is possible to improve the quality of the metal. The content of residual elements is according to GOST 5632. The content of Ti% = 5 · (С -0.02)% is 0.7%.