Steel 08KH18G8N2T (KO-3)

Designation

Name	The value
Designation GOST Cyrillic	08Х18Г8Н2Т
Designation GOST Latin	08X18G8H2T
Transliteration	08H18G8N2T
By chemical elements	08Cr18Mn8Н2Ti

Name	The value
Designation GOST Cyrillic	КО-3
Designation GOST Latin	KO-3
Transliteration	KO-3
By chemical elements	CoО-3

Description

Steel 08KH18G8N2T applies: it is recommended as a substitute for steel grades 08KH18N10T and 12KH18N10T (has higher strength) for the manufacture of welded equipment operating in aggressive environments in the chemical, food and other industries at the operating temperature from -50 to +300 °C.

Note

Austenite corrosion resistant steel-ferritic class.

Standards

Name	Code	Standards
Processing of metals by pressure. Forgings	В03	GOST 25054-81
Classification, nomenclature and General rules	В30	GOST 5632-72
Sheets and strips	В33	GOST 7350-77
Blanks. Of the workpiece. Slabs	В31	OST 3-1686-90, TU 14-1-1345-74
Thermal and thermochemical treatment of metals	В04	STP 26.260.484-2004
Bars and shapes	В32	TU 14-1-4687-89, TU 14-11-245-88

Chemical composition

Standard	C	S	P	Mn	Cr	Si	Ni	Fe	Cu	V	Ti	Mo	W
GOST 5632-72	≤0.08	≤0.025	≤0.035	7-9	17-19	≤0.8	1.8-2.8	Rest	≤0.3	≤0.2	0.2-0.5	≤0.3	≤0.2

Fe is the basis.

Mechanical properties

Section, mm	s_T\|s_0,2, MPa	σ_U, MPa	d₅, %	y, %	KCU, kJ/m²	HB, MPa
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 under a water shower from 980-1020 °C
	≥345	≥590	≥20	-	≥588	-
Long products (samples). Quenching in water from 1000 °C + Aging (aging during aging for 1 h) (in the column test temperature is the temperature of aging)
-	≥415	≥820	≥32	≥50	-	-
Long products (samples). Quenching in water from 1000 °C
-	≥80	≥90	≥45	≥65	-	-
Long products (samples). Quenching in water from 1000 °C (provided the degree of deformation in %)
-	≥390	≥650	≥22	-	-	-
Bars hot rolled and forged at STP 26.260.484-2004. Quenching in water or air from 950-1050 °C
	≥350	≥600	≥20	≥30	≥588	-
Long products (samples). Quenching in water from 1000 °C + Aging (aging during aging for 1 h) (in the column test temperature is the temperature of aging)
-	≥410	≥800	≥31	≥50	-	-
Long products (samples). Quenching in water from 1000 °C
-	≥40	≥50	≥45	≥70	-	-
Long products (samples). Quenching in water from 1000 °C (provided the degree of deformation in %)
-	≥700	≥820	≥16	-	-	-
Long products (samples). Quenching in water from 1000 °C + Aging (aging during aging for 1 h) (in the column test temperature is the temperature of aging)
-	≥390	≥790	≥32	≥52	-	-
Long products (samples). Quenching in water from 1000 °C
-	≥15	≥20	≥60	≥80	-	-
Long products (samples). Quenching in water from 1000 °C (provided the degree of deformation in %)
-	≥780	≥880	≥6	-	-	-
Long products (samples). Quenching in water from 1000 °C + Aging (aging during aging for 1 h) (in the column test temperature is the temperature of aging)
-	≥380	≥780	≥28	≥57	-	-
Long products (samples). Quenching in water from 1000 °C
-	≥5	≥10	≥70	≥85	-	-
Long products (samples). Quenching in water from 1000 °C (provided the degree of deformation in %)
-	≥660	≥780	≥19	-	-	-
Long products (samples). Quenching in water from 1000 °C + Aging (aging during aging for 1 h) (in the column test temperature is the temperature of aging)
-	≥390	≥780	≥28	≥57	-	-
Long products (samples). Quenching in water from 1000 °C (provided the degree of deformation in %)
-	≥1080	≥1100	≥3	-	-	-
Long products (samples). Quenching in water from 1000 °C
-	-	-	≥80	≥90	-	-
Long products (samples). Quenching in water from 1000 °C + Aging (aging at aging 100 h) (in the column test temperature is the temperature of aging)
-	≥410	≥810	≥32	≥49	-	200-210
-	≥450	≥850	≥27	≥48	-	240-260
-	≥410	≥760	≥29	≥48	-	230-240
-	≥370	≥780	≥24	≥38	-	285-325
-	≥510	≥810	≥10	≥12	-	325

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

Physical characteristics

Temperature	Е, HPa	r, kg/m³	l, W/(m · °C)	R, Mr. · m	a, 10^-6 1/°C	С, J/(kg · °C)
0	212	7700	21	710	-	-
20	212	7700	21	710	-	-
100	203	-	-	-	123	462
200	195	-	-	-	131	-
300	184	-	-	-	144	462
400	177	-	-	-	144	-
500	164	-	-	-	153	-
600	167	-	-	-	166	-
700	146	-	-	-	16	-
800	161	-	-	-	-	-
900	-	-	-	-	164	-
1100	-	-	-	-	172	-

A description of the physical symbols

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

Technological properties

Name	The value
Weldability	without restrictions. Steel is well welded RDS and ADS. Are recommended for manual welding electrodes CL-11 (SV-08Х19Н10Б). For automatic welding using a wire of steel or 08Х19Н10Б 08Х20Н9Г7Т in combination with flux an-26.
The temperature of forging	Start - 1150 °C, end - 810 °C.
Features of heat treatment	Steel products to eliminate the tendency to intergranular corrosion are subjected to hardening regime: heating to 950-1050 °C, exposure during heating for quenching for products with wall thickness up to 10 mm - 30 min, over 10 mm — 20 min + 1 min per 1 mm max thickness cooling in water or air. Products austenite-ferritic steels do not require heat treatment after welding.