Steel 07KH21G7AN5 (ЭП222)

Designation

Name	The value
Designation GOST Cyrillic	07Х21Г7АН5
Designation GOST Latin	07X21G7AH5
Transliteration	07H21G7AN5
By chemical elements	07Cr21Mn7NН5

Name	The value
Designation GOST Cyrillic	ЭП222
Designation GOST Latin	EP222
Transliteration	EhP222
By chemical elements	-

Description

07KH21G7AN5 steel is used: for the manufacture of welded components, spindles, hangers, oxygen, brazed structures, special fasteners, flanges, threaded connections with high svenimento operating at temperatures from +400 °C to -253 °C and in environments of medium aggressiveness; parts and welded assemblies of valves in the heat treated condition.

Note

Steel corrosion resistant.
Unstabilized chromium-Nickel steel of austenitic class.
Steel resistant to marine water.

Standards

Name	Code	Standards
Classification, nomenclature and General rules	В30	GOST 5632-72
Bars and shapes	В32	GOST 5949-75, GOST 14955-77, TU 14-1-1141-74, TU 14-1-952-74, TU 14-11-245-88
Blanks. Of the workpiece. Slabs	В31	OST 3-1686-90
Thermal and thermochemical treatment of metals	В04	STP 26.260.484-2004, ST ЦКБА 016-2005
Processing of metals by pressure. Forgings	В03	TU 14-1-1530-75, ST ЦКБА 010-2004
Sheets and strips	В33	TU 14-1-2455-78, TU 14-1-2476-78

Chemical composition

Standard	C	S	P	Mn	Cr	Si	Ni	Fe	Cu	N	V	Ti	Mo	Ca	W	Ce
TU 14-1-1141-74	≤0.07	≤0.03	≤0.03	6-7.5	19.5-21	≤0.7	5-6	Rest	≤0.3	0.15-0.25	≤0.2	-	≤0.2	-	≤0.2	-
GOST 5632-72	≤0.07	≤0.03	≤0.03	6-7.5	19.5-21	≤0.7	5-6	Rest	≤0.3	0.15-0.25	≤0.2	≤0.2	≤0.3	-	≤0.2	-
TU 14-1-952-74	≤0.07	≤0.015	≤0.03	6-7.5	19.5-21	≤0.7	5-6	Rest	≤0.3	0.15-0.25	≤0.2	-	≤0.2	-	≤0.2	-
TU 14-1-2476-78	≤0.07	≤0.03	≤0.03	6-7.5	19.5-21	≤0.7	5-6	Rest	≤0.3	0.15-0.25	≤0.2	≤0.2	≤0.3	≤0.02	≤0.2	≤0.02

Fe is the basis.
According to TU 14-1-1141-74, the chemical composition is given for steel grade 07Х21Г7АН5 (Х21Г7АН5, ЭП222). According to TU 14-1-952-74, the chemical composition is given for steel grade 07X21G7AN5-SH (X21G7AN5-SH, EP222-SH). According to the technical specification, deviations from the content of elements are allowed: for carbon +0.010%, for chromium ± 0.30%, for manganese + 0.25%, for nitrogen +0.050%. Cerium and calcium are introduced into the steel in an amount not exceeding 0.020% each, which are introduced into the metal by calculation and chemical analysis are not determined.
According to GOST 5632-72, the chemical composition is given for steel grade 07Х21Г7АН5.
According to TU 14-1-2476-78, the chemical composition is given for steel grade 07Х21Г7АН5 (ЭП222), 07Х21Г7АН5-ВД (ЭП222-ВД), 07Х21Г7АН5-Ш (ЭП222-Ш). Cerium and calcium are introduced into the steel in an amount not exceeding 0.020% each, the content of which in the steel is not determined by chemical analysis. Deviations in chemical composition are allowed in the finished product in accordance with GOST 5632.

Mechanical properties

Section, mm	s_T\|s_0,2, MPa	σ_U, MPa	d₅, %	y, %	KCU, kJ/m²	HB, MPa
Hot rolled and forged products with a diameter of 10-180 mm of steel grade 07KH21G7AN5 on the other 14-1-1141-74. Annealing in air or in water with 1000-1050 °C
	≥365	≥690	≥40	≥50	≥1270	-
Hot rolled and forged products with a diameter of 10-180 mm of steel grade 07KH21G7AN5-W on the other 14-1-952-74. Annealing in air or in water with 1000-1050 °C
	≥333	≥657	≥40	≥50	≥1280	-
Blank pieces of pipe fittings according to ST CKBA 016-2005. Quenching in water or air 1000-1050 °C (aging of 1.0 to 1.5 min/mm of maximum cross section but not less than 0.5 h)
≤60	≥363	≥686	≥40	≥50	≥1275	≤207
≤60	≥333	≥657	≥40	≥50	≥1275	≤207
Cold-rolled sheet (0.7 to 5.0 mm) and hot-rolled steel (3,0-6,0 mm) made of steel 07KH21G7AN5 in the delivery condition on the other 14-1-2476-78. Quenching in water or air with 1020-1050 NN the fire °C
-	≥392	≥735	≥25	-	-	-
Bars hot rolled and forged according to GOST 5949-75. Annealing in air or in water with 1000-1050 °C
	≥365	≥690	≥40	≥50	≥1274	-
Bars hot rolled and forged at STP 26.260.484-2004. Quenching in water or air from 1050-1100 °C
	≥400	≥700	≥25	-	-	-

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

Technological properties

Name	The value
Weldability	To improve the toughness of welded joints at the operating temperature, if the product operates at cryogenic temperatures used for tempering the air from 950-1050 °C (aged for at least 2.5 minutes/mm of maximum wall thickness, but not less than 1 hour).
Macrostructure and pollution	On the other 14-1-952-74 macrostructure of steel when tested for transverse slacked templeto without the use of magnifying devices should not have bubbles, captivity, cracks, fistulas, inclusions, podsadecki segregation and exudation of the square. Defects in the macrostructure should not exceed the Central porosity score of 1.0; for a point heterogeneity, a score of 2.0; layer-by-layer crystallization - score of 3.0; bright, contour score of 3.0. Pollution steel non-metallic inclusions shall not exceed: - silicates fragile (CX) - score of 1.0; silicates plastic (SP) - score of 1.0; - the non-deformable silicates (SN) is a score of 2.0; the sulphides (A) - score of 1.0; - stroke nitrides (NA) - score of 2.0; the nitrides of the point (NT) - score of 2.0; - oxides of stroke (OS) - score of 2.0; the point oxides (FROM) - score of 2.0. Quality control of metal-to-foloowing is the consumer in accordance with the requirements of TU 14-1-336-72. On the other 14-1-1141-74 macrostructure of steel when tested for transverse slacked templeto without the use of magnifying devices should not have traces of shrinkage, bubbles, captivity, cracks, fistulas, slag inclusions. On microtemplate presence of defects, if the value does not exceed the standards shown in table 3 according to the scales GOST 10243. Defects in the macrostructure should not exceed the Central porosity score of 1.0; for a point heterogeneity, a score of 1.0; in the exudation of the square - a score of 1.0; for podsadecki segregation - score of 1.0. Increased or reduced travelmasti of the axial zone is not a rejection symptom.
Features of heat treatment	Steel used for products, not subjected to welding is designed to work in environments do not cause intergranular corrosion. To increase the resistance against General corrosion and eliminate the tendency to intergranular corrosion and to improve the ductility of the workpiece material is subjected to annealing regime: heating to 1050-1100 °C, cooling in water. 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.