Steel 12Х18Н12Т (Х18Н12Т)

Designation

Name	The value
Designation GOST Cyrillic	12Х18Н12Т
Designation GOST Latin	12X18H12T
Transliteration	12H18N12T
By chemical elements	12Cr18Н12Ti

Name	The value
Designation GOST Cyrillic	Х18Н12Т
Designation GOST Latin	X18H12T
Transliteration	H18N12T
By chemical elements	Cr18Н12Ti

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

Name	Code	Standards
Bars and shapes	В22	GOST 1133-71, GOST 2590-2006, GOST 2591-2006, GOST 2879-2006
Test methods. Packing. Marking	В09	GOST 11878-66
Sheets and strips	В23	GOST 19903-74, GOST 19904-90, GOST 103-2006, GOST 19903-90
Sheets and strips	В33	GOST 4405-75, GOST 7350-77
Classification, nomenclature and General rules	В30	GOST 5632-72
Bars and shapes	В32	GOST 5949-75, GOST 7417-75, GOST 8559-75, GOST 8560-78, GOST 14955-77, TU 14-11-245-88, TU 14-1-1529-2003
Steel pipes and fittings to them	В62	GOST 9940-81, GOST 9941-81, GOST 14162-79, TU 14-159-165-87, TU 14-3-1109-82, TU 14-158-135-2003, TU 14-3-460-2009, TU 14-3Р-110-2009, TU 14-3Р-55-2001, TU 14-158-137-2003, TU 14-3-460-2003, TU 14-3-1654-89
Blanks. Of the workpiece. Slabs	В31	OST 3-1686-90, OST 95-29-72, TU 108-938-80, TU 14-1-1214-75, TU 14-1-565-84
Welding and cutting metals. Soldering, riveting	В05	OST 95 10441-2002
Castings, non-ferrous metals and alloys	В84	RD 9257-76
Thermal and thermochemical treatment of metals	В04	STP 26.260.484-2004

Chemical composition

Standard	C	S	P	Mn	Cr	Si	Ni	Fe	Cu	V	Mo	W
TU 14-1-1529-2003	≤0.12	≤0.02	≤0.035	1-2	17-19	≤0.8	11-13	Rest	≤0.3	≤0.2	≤0.5	≤0.2
TU 14-3Р-55-2001	≤0.12	≤0.015	≤0.03	1-2	17-19	≤0.8	11-13	Rest	≤0.3	-	-	-
GOST 5632-72	≤0.12	≤0.02	≤0.035	≤2	17-19	≤0.8	11-13	Rest	≤0.4	≤0.2	≤0.5	≤0.2
TU 14-158-137-2003	≤0.12	≤0.02	≤0.035	≤2	17-19	≤0.8	11-13	Rest	-	-	-	-
TU 14-3-460-2003	≤0.12	≤0.025	≤0.035	1-2	17-19	≤0.8	11-13	Rest	≤0.3	≤0.2	≤0.5	≤0.2

Fe is the basis.
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%.

Mechanical properties

Section, mm	s_T\|s_0,2, MPa	σ_U, MPa	d₅, %	d₄	y, %	KCU, kJ/m²	HB, MPa
Tubes of small dimensions (capillary) heat-treated or cold-worked in the state of delivery according to GOST 14162-79
	-	≥510	≥26	-	-	-	-
Billet (forgings) OST 95-29-72 in the state of delivery: Austenization at 1020-1100 °C, cooling in water or air
	≥196	≥540	≥40	-	-	-	-
Rolled steel. Annealing in air from 1050-1100 °C
-	225-315	550-640	46-74	-	66-80	215-372	-
Billet (forgings) OST 95-29-72 in the state of delivery: Austenization at 1020-1100 °C, cooling in water or air
	≥176	≥352	-	-	-	-	-
Rolled steel. Annealing in air from 1050-1100 °C
-	140-205	390-440	30-42	-	60-70	196-353	-
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 air from 1030-1080 °C
-	≥235	≥530	≥38	-	-	-	-
Rolled steel. Annealing in air from 1050-1100 °C
-	140-205	380-450	31-41	-	61-68	215-353	-
Rolled sheet. Quenching in water or air from 1050-1080 °C
0.8-3.9	-	≥540	-	≥35	-	-	-
Rolled steel. Annealing in air from 1050-1100 °C
-	120-205	340-410	28-38	-	51-74	196-353	-
Bars hot rolled and forged according to GOST 5949-75. Quenching in air, oil or water with 1020-1100 °C
	≥196	≥540	≥40	-	≥55	-	-
Rolled steel. Annealing in air from 1050-1100 °C
-	120-195	270-390	27-37	-	52-73	245-353	-
Bars hot rolled and forged at STP 26.260.484-2004. Quenching in water or air from 1000-1080 °C
	≥180	≥500	≥40	-	≥55	-	-
Rolled steel. Annealing in air from 1050-1100 °C
-	120-195	265-350	20-38	-	40-70	255-353	-
Tubular billet + hot deformed Tubes (DH=57-465 mm) TU 14-3-460-2003. Austenization with 1000-1200 °C, cooling in air or in water (longitudinal sample)
	≥215	530-690	≥35	-	≥55	-	≤200
Seamless hot deformed tubes in the delivery condition according to GOST 9940-81
	-	≥529	≥40	-	-	-	-
Seamless pipes for steam boilers and pipelines according to TU 14-3P-55-2001. Austenization at 1100-1200 °C, air cooling or water
-	216-392	539-686	≥35	-	≥55	-	≤190
Pipe gorjachekatanye seamless. Without heat treatment (specified wall thickness, the longitudinal sample)
3.5-32	210-220	529-540	≥40	-	≥55	-	-
Pipe cold - and warm seamless, cold-and warm superior quality. Quenching in water or air from 1030-1080 °C (specified wall thickness, the longitudinal sample)
0.2-32	-	≥549	≥35	-	-	-	-

Description mechanical marks

Name	Description
s_T\|s_0,2	Yield strength or limit of proportionality with a tolerance for residual deformation of 0.2%
σ_U	Limit short-term strength
d₅	Elongation after rupture
d₄	Elongation after rupture
y	The relative narrowing
KCU	Toughness
HB	Brinell hardness number

Physical characteristics

Temperature	Е, HPa	G, HPa	r, kg/m³	l, W/(m · °C)	R, Mr. · m	a, 10^-6 1/°C	С, J/(kg · °C)
0	210	77	7950	15	725	-	-
20	205	-	7900	151	761	-	-
100	198	-	7870	1633	792	166	460
200	193	-	7830	1758	861	17	482
300	186	-	7780	1884	920	172	507
400	177	-	7740	2135	976	175	525
500	170	-	7700	2303	1028	179	545
600	157	-	7850	2470	1075	182	563
700	147	-	7610	2680	1117	186	579
800	-	-	7560	2800	1155	189	590
900	-	-	7510	291	1210	189	603
1000	-	-	-	308	1245	-	616
1100	-	-	-	323	1275	193	625
1200	-	-	-	341	1315	-	637

A description of the physical symbols

Name	Description
Е	The normal elasticity modulus
r	Density
l	Coefficient of thermal conductivity
R	UD. the resistivity
a	The coefficient of linear expansion

Technological properties

Name	The value
Weldability	Satisfactory weldability. Welding methods: SMAW electrodes DH-15-1 for the root of the weld, CG-15 for the subsequent layers. CT-26 for those cases where no requirements for resistance to the ICC, CBS and ESW. Recommended subsequent heat treatment. For joints of NPP equipment recommended automatic arc welding under flux.
The temperature of forging	Start - 1200 °C, the end - 850 °C. the cross Sections up to 350 mm cooled in air.
Machinability	Has satisfactory machinability. In the hardened state when HB 170 and blower SB=470 MPa Kn TV.SPL.=0,85 Kn b.St.=0,35.
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.