Steel 07KH16N6 (ЭП288; SN-2A; Х16Н6)

Designation

Name	The value
Designation GOST Cyrillic	07Х16Н6
Designation GOST Latin	07X16H6
Transliteration	07H16N6
By chemical elements	07Cr16Н6

Name	The value
Designation GOST Cyrillic	ЭП288
Designation GOST Latin	EP288
Transliteration	EhP288
By chemical elements	-

Name	The value
Designation GOST Cyrillic	СН-2А
Designation GOST Latin	CH-2A
Transliteration	SN-2A
By chemical elements	СН-2

Name	The value
Designation GOST Cyrillic	Х16Н6
Designation GOST Latin	X16H6
Transliteration	H16N6
By chemical elements	Cr16Н6

Description

07KH16N6 steel is used: for the manufacture of products, working in atmospheric conditions, acetic acid and other saline environments; elastic elements; welding wire used for welding parts and welding of steel structures in energy engineering; welding electrodes; power locks, designed for locking of hatches of aircraft and helicopters; bolts, flanges, screws, nuts and body parts for aircraft; high-strength parts operating for a long period of time at temperatures up to +500−550 °C.

Note

Stainless steel austenitic-martensitic class, has no Delta ferrite.

Standards

Name	Code	Standards
Processing of metals by pressure. Forgings	В03	GOST 25054-81, TU 14-1-1530-75, TU 14-1-2902-80, TU 14-1-2918-80
Sheets and strips	В33	GOST 5582-75, GOST 7350-77, TU 14-1-1558-76, TU 14-1-2375-77, TU 14-1-2476-78, TU 14-1-763-73
Classification, nomenclature and General rules	В30	GOST 5632-72
Bars and shapes	В32	GOST 5949-75, TU 14-1-1660-76, TU 14-1-205-72, TU 14-136-331-89, TU 14-1-759-73, TU 14-11-245-88, TU 14-1-759-92
Classification, nomenclature and General rules	В20	OST 1 90005-91
Blanks. Of the workpiece. Slabs	В21	OST 1 90176-75
Blanks. Of the workpiece. Slabs	В31	OST 3-1686-90, TU 14-1-1213-75, TU 14-1-1214-75
Thermal and thermochemical treatment of metals	В04	STP 26.260.484-2004
Welding and cutting metals. Soldering, riveting	В05	TU 14-1-997-74, TU 14-1-997-2012
Steel pipes and fittings to them	В62	TU 14-3-1334-85

Chemical composition

Standard	C	S	P	Mn	Cr	Si	Ni	Fe	Cu	V	Ti	Mo	Nb	W
TU 14-1-2902-80	0.05-0.09	≤0.02	≤0.035	≤0.8	15.5-17.5	≤0.7	5-8	Rest	≤0.2	≤0.2	≤0.05	≤0.3	≤0.15	≤0.2
TU 14-1-997-74	0.05-0.09	≤0.02	≤0.035	≤0.8	15.5-17.5	≤0.8	5-8	Rest	≤0.2	-	-	-	-	-
TU 14-1-1660-76	0.05-0.09	≤0.015	≤0.03	≤0.8	15.5-17.5	≤0.7	5-8	Rest	≤0.2	≤0.2	≤0.05	≤0.2	≤0.15	≤0.2
TU 14-1-1558-76	0.05-0.09	≤0.02	≤0.035	-	15.5-17.5	≤0.8	5-8	Rest	-	-	-	-	-	-
TU 14-1-2375-77	0.05-0.09	≤0.02	≤0.035	≤0.8	15.5-17.5	≤0.7	5-8	Rest	≤0.3	-	-	-	-	-
GOST 5632-72	0.05-0.09	≤0.02	≤0.035	≤0.8	15.5-17.5	≤0.8	5-8	Rest	≤0.3	≤0.2	≤0.05	≤0.3	-	≤0.2
TU 14-1-759-92	0.05-0.09	≤0.015	≤0.035	≤0.8	15.5-17.5	≤0.7	5-8	Rest	≤0.3	-	-	-	-	-
TU 14-1-2918-80	0.05-0.09	≤0.02	≤0.035	≤0.8	15.5-17.5	≤0.7	5-8	Rest	≤0.3	≤0.2	≤0.05	≤0.3	-	≤0.2

Fe is the basis.
According to TU 14-1-1660-76 the chemical composition is given for steel grade 07H16N6-III. In steel for limited use, the content of residual elements should not exceed: tungsten, vanadium, molybdenum, copper - 0.20% each, niobium - 0.15%, titanium - 0.050%. The content of residual elements is allowed not to be determined.
According to TU 14-1-2902-80 and TU 14-1-2918-80 the chemical composition is given for 07Х16Н6 and 07Х16Н6-Ш.
According to TU 14-1-2918-80, the sulfur content in steel EP288-III, smelted by electroslag remelting, should not exceed 0.015%. At the request of the consumer the steel grade EP288 and EP288-SH are supplied with a phosphorus content of not more than 0.025%.
According to TU 14-1-1558-76 the chemical composition is given for steel grade 07H16N6. If the other requirements of the specifications are satisfied, ready deviations from the chemical composition standards and residual elements within the limits of GOST 5632 are allowed in the finished thin-sheet steel.
According to TU 14-1-2375-77, the chemical composition is given for steel grades 07Х16Н6 and 07Х16Н6-Ш. If the requirements of TU are met, the following chemical composition tolerances are allowed: for chromium minus 0.50%; for silicon and manganese, plus 0.020% of each.
According to TU 14-1-1213-75, the mass fraction of residual elements should not exceed: copper, vanadium, tungsten - 0.20% each for limited use in steel 07Х16Н6 (ЭП288) and 07Х16Н6-Ш (ЭП288-Ш), molybdenum - 0 , 30%, niobium 0.15%, titanium 0.050%. The determination of the mass fraction of the residual elements is not allowed. The steel is marked in this case: 07Х16Н6У (ЭП288У) and 07Х16Н6У-Ш (ЭП288У-Ш).
According to TU 14-1-2476-78, the chemical composition is given for steel grades 07Х16Н6, 07Х16Н6-ВД and 07Х16Н6-Ш. In the finished product, deviations in chemical composition are allowed in accordance with GOST 5632. For limited use in steel 07Х16Н6 and 07Х16Н6-Ш the content of residual elements in steel should not exceed: copper, vanadium, tungsten 0.20% each, molybdenum 0.30 %, niobium - 0.15%, titanium - 0.050%. The content of the residual elements can not be determined. In this case the steel is marked with 07Х16Н6У (ЭП288У), 07Х16Н6У-Ш (ЭП288У-Ш).
According to TU 14-1-759-92 the chemical composition is given for steel grade 07H16N6-SH. Allowed, subject to all the requirements of the technical specification, the chromium deflection is -0.50%. For limited use in steel 07H16N6-SH, the content of residual elements in steel should not exceed: copper, vanadium, tungsten 0.20% each, molybdenum 0.30%, niobium 0.15%, titanium 0.050%. The content of the residual elements can not be determined. In this case the steel is marked with 07Х16Н6У-Ш (ЭП288У-Ш).

Mechanical properties

Section, mm	s_T\|s_0,2, MPa	σ_U, MPa	d₅, %	y, %	KCU, kJ/m²	HB, MPa	HRC
Gradation of performance properties of the finished heat-treated parts for OST 1 90005-91
-	-	1080-1370	-	-	-	311-388	34-41
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 with 1030-1070 °C
-	-	≤1180	≥20	-	-	-	-
Hot rolled sheet (of 1.5-3.9 mm) and cold rolled (0,7-3,9 mm) steel according to GOST 5582-75. Annealing in air 960-990 °C cold treatment at minus 70 °C for 2 h+ Vacation at 350-400 °C (aging for 1 h), air cooling
	≥835	≥1080	≥12	-	-	-	-
Hot rolled sheet (2.0 to 3.9 mm) and cold rolled (0.8-3.0 mm) steel TU 14-1-1558-76 in the delivery condition. Quenching in water or air with 1040-1060 °C
	-	≥1275	≥20	-	-	-	-
Hot rolled sheet (2.0 to 3.9 mm) and cold rolled (0.8-3.0 mm) steel TU 14-1-1558-76. Hardening in air, 970-990 °C + cold Treatment at minus 70±5 °C (aging for 2 h±10 min) or at minus 50±5 °C (exposure for 4 h±10 min) + Vacation at 350-400 °C (aging 1 HR+10 min)
	≥833	≥1079	≥12	-	-	-	-
Hot rolled sheet (3,0-6,0 mm) and cold rolled (1.0 to 4.0 mm) to rent in the state at rates THAT 14-1-2375-77. Hardening in air, 1030-1070 °C
	≤390	≤1180	≥20	-	-	-	-
Hot rolled sheet (3,0-6,0 mm) and cold rolled (1.0 to 4.0 mm) steel on the other 14-1-2375-77. Normalization with 965-985 °C, air cooling + cold Treatment at -70 °C (2 hours) + Vacation at 350-425 °C (exposure for 1 hour)
	≥835	≥1080	≥12	-	-	-	-
Hot rolled sheet (4,0-50,0 mm) and cold rolled (4,0-5,0 mm) steel according to GOST 7350-77. Normalization at 1030-1050 °C, air cooling
-	≤390	≤1180	≥15	-	-	-	-
Hot rolled sheet (4,0-50,0 mm) and cold rolled (4,0-5,0 mm) steel according to GOST 7350-77. Normalization at 965-985 °C + cold Treatment at minus 70 °C for 2 h + Vacation at 415-435 °C (aging for 1 h), air cooling
	≥835	≥1080	≥10	-	-	-	-
Cold-rolled sheet (0.7 to 5.0 mm) and hot-rolled steel (3,0-6,0 mm) made of steel 07KH16N6 in the state of delivery on the other 14-1-2476-78. Quenching in water or air with 1040-1060 °C
-	-	≤1177	≥20	-	-	-	-
Cold-rolled sheet (0.7 to 5.0 mm) and hot-rolled steel (3,0-6,0 mm) made of steel 07KH16N6 on the other 14-1-2476-78. Annealing in air from 990 °C + cold Treatment at -70 °C for 2 hours + vacation at 250 °C (exposure 2 hours), air cooling
	≥834	1079	≥12	-	-	-	-
Cold-rolled sheet (0.7 to 5.0 mm) and hot-rolled steel (3,0-6,0 mm) made of steel 07KH16N6 on the other 14-1-2476-78. Annealing in air from 990 °C + cold treatment at -70 °C for 2 hours + Vacation at 350-400 °C (exposure for 1 hour), cooling air
	≥834	≥108	≥12	-	-	-	-
Forgings. Quenching in water with 975-1000 °C, followed by cold treatment at minus 70 °C, exposure for 2 hours + aged at 350-425 °C (aging for 1 h), air cooling
≤1000	≥980	≥1176	≥12	≥50	≥680	-	-
	≥885	≥1080	≥15	≥50	≥680	-	-
Bars grooved and SOS special surface finish on the other 14-1-759-92. The longitudinal samples. Normalization with 1090-1110 °C + cold Treatment at minus 70 °C±10 ° C (exposure for 2 hours ± 5 minutes) + Vacation at 375-400 °C (exposure for 1 hour ± 5 minutes), air cooling
	≥980	≥1180	≥12	≥50	≥686	-	-
Bars on the other 14-1-1660-76. Quenching in water with 975-1000 °C + cold Treatment at minus 70±5 °C (2 hours) + Vacation at 350-390 °C (extract 1-3 hours)
	≥981	≥1177	≥12	≥55	≥883	-	-
Bars hot rolled and forged according to GOST 5949-75. Quenching in water, in air or in oil with 975-1000 °C + cold Treatment at minus 70 °C (extract 2 h) or at minus 50 °C (exposure 4 h) + Aging at 350-400 °C (aging for 1 h), air cooling
	≥880	≥1080	≥12	≥50	≥686	-	-
Bars hot rolled and forged at STP 26.260.484-2004. Quenching in water or air from 980-1020 °C, cold treatment at -10 °C (exposure 2 hours) + Vacation at 180-200 °C, air cooling
	≥700	≥950	≥20	≥60	≥1176	-	-
Bars hot rolled and forged at STP 26.260.484-2004. Quenching in water or air from 980-1020 °C, cold treatment at -70 °C (exposure 2 hours) + Aging at 350-380 °C, air cooling
	≥1000	≥1200	≥12	≥50	≥686	-	-
Bars hot rolled and forged at STP 26.260.484-2004. Quenching in water or air from 980-1020 °C, cold treatment at -70 °C (exposure 2 hours) + Aging at 400-450 °C, air cooling
	≥1050	≥1250	≥10	≥45	≥490	-	-
Forming at OST 1 90176-75. Quenching in air, water 980-1000 °C + cold Treatment at minus 70°C (2 h) or -50 °C (4 hours) + Vacation at 350-380 °C (aging 1 HR)
	≥981	≥1177	≥12	≥50	≥686	-	-

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
y	The relative narrowing
KCU	Toughness
HB	Brinell hardness number
HRC	Rockwell hardness (indenter diamond spheroconical)

Technological properties

Name	The value
Macrostructure and pollution	Macrostructure of steel shall be no traces of shrinkage, delamination, foreign inclusions. The macrostructure of bars on the other 14-1-759-92 must be without voids, cracks, cracks, delamination, inclusions visible to the naked eye. The defects allowed in scores on scales GOST 10243 Central porosity, spot inhomogeneity and phase separation in the square should not exceed 1 point for each parameter.
Features of heat treatment	After quenching, the steel has a structure of unstable austenite with a small amount of martensite. In this state, the steel doesn't strengthen aging. Hardening as a result of ageing after pre-deformation or cold treatment products that causes the formation of martensite. Parts, components and apparatus made of nettervibration sheets, strips, extruded profiles, as well as from bars, rods and forgings, are subjected to full cycle of hardening heat treatment: a) annealing (for obtaining a structure of austenite); b) cold treatment at minus 70 °C (aging for at least 2 h, while cooling in the refrigerating chamber, the exposure time is doubled); C) aging (to achieve a specified level of properties). Products, to achieve maximum corrosion resistance, is subjected to heat treatment by mode: heating to 1000±20 °C, exposure with wall thickness up to 15 mm - 30 min; more than 15 mm - 30 min + 1-2 min per 1 mm of maximum wall thickness; cooling in water or air; cold treatment; aging at 350-380 °C, dwell time 1 hour + 1 min per 1 mm cross section; the cooling air. To obtain maximum strength characteristics of aging must be carried out at 400-480 °C, dwell time 1 hour + 1 min per 1 mm cross section, but the steel acquires the tendency to intergranular corrosion. In the hardening of products with wall thickness up to 8 mm, the cooling is carried out on the tranquil air, the products wall thickness more than 8 mm, and also products from bar and forgings are cooled in water. Slow cooling of products (with oven or in bulk) are not allowed. The gap between the operations of quenching and cold treatment should not exceed 12h. Before cold processing products shall not be subjected to heating or exposure to temperatures from 0 to minus 40 °C. cooling Time of the product from room temperature to minus 70 °C should be minimal. When obtaining low values of relative narrowing and toughness in comparison with specified in the normative documents, what is usually observed in large forgings, it is recommended obezvrezivate annealing regime: heating to 500±10 °C , exposure 30 h for sections up to 50 mm and 50 h for sections more than 50 mm. the Highest rate of bezodiazepine observed in the martensitic structure, so before bezodiazepines structure of the steel is transferred to a martensitic state by heat treatment at minus 70 °C. To obtain the desired properties after obezbolivaushee heat treatment necessary heat treatment for hardening of the regime . When hardening heat treatment products there is an increase in their size compared to tempered as 0.3-0.5 %. To obtain a yield strength of 70-80 kg/mm2 (700-800 MPa): products used for the treatment of: a) annealing according to ; b) cold treatment at a temperature of from 0 °C to minus 10 °C for 2H; C) leave at 200 °C for 2H. For best machinability steel products 07KH16N6 subjected to double heat treatment: annealing at 760-780°, exposure is 1.5-2 hours, air cooling, leave at 650-680 °C for 1.5-2 h, air cooling.