Steel 20X25H20C2

Steel 20X25H20C2: a classifier of steels and alloys. Below is systematized information on the purpose, chemical composition, types of supply, substitutes, critical point temperature, physical, mechanical, technological and foundry properties for the grade — Steel 20X25N20C2.

General information on steel 20X25H20C2

Delivery type

Sheet 20х25Н20с2, bars, including shaped: GOST 5949−75, GOST 2590−71, GOST 2591−71, GOST 2879−69. Calibrated bar GOST 7417−75, GOST 8559−75, GOST 8560−78. Grinded rod and silver GOST 14955−77. Sheet thin GOST 5582−75, GOST 19903−74, GOST 19904−74. Strip GOST 4405−75, GOST 103−76. Forgings and forged blanks GOST 1133−71.

Application

The parts of the furnaces operating at temperatures up to 1100 °C in the air and hydrocarbon atmospheres. Heat-resistant steel of the outtense class.

Chemical composition of steel 20X25H20S2

Chemical element	%
Vanadium (V), not more	0.2
Tungsten (W), not more	0.2
Silicon (Si)	2.0−3.0
Manganese (Mn), not more than	1.5
Copper (Cu), not more than	0.30
Molybdenum (Mo), not more than	0.30
Nickel (Ni)	18.0−21.0
Sulfur (S), not more than	0.020
Titanium (Ti), not more than	0.2
Carbon ©, not more than	0.20
Phosphorus (P), not more than	0.035
Chrome (Cr)	24.0−27.0

Mechanical properties of steel 20X25H20C2

Heat treatment, delivery condition	Section, mm	σ0_.2, MPa	_σB, MPa	_δ5, %	ψ, %
Rods. Hardening 1100−1150°C, air or water.	60	295	590	35	50
Hot- and cold-rolled sheets. Hardened 1050−1100°C, water or air. (crosswise samples)	<3,9		490	35

Mechanical properties at elevated temperatures

t test,°C	σ0_{, 2}, MPa	_σB, MPa	_δ5, %	ψ, %
500	255	520	30	47
600	210	490	35	50
700	165	320	40	55
800	110	195	50	63

Mechanical properties in the long term strength test

Creep strength, MPa	Creep rate, %/h	t test,°C	Ultimate long-term strength, MPa	Test duration, h	t test, h
4	0.5/1000	875	37	100	875
5	1/1000	875	22	1000	875
10	1/1000	1000	20	100000	800
			7	100000	900

Technological properties of steel 20X25H20C2

Forging temperature

Beginning 1170, end 850. Cooling in the air.

Tendency to tempering

inclined in the range of 600−800 C due to the formation of b-phase (GOST 5632−72).

Heat resistance of steel 20X25H20C2

Medium	Temperature,°C	Depth, mm/year	Resistance group or grade
Air	875	0,117	6
Air	1050	0,476	6
Air	1200	1,404	Low-resistant

Physical properties of steel 20Х25Н20С2

Test temperature,°C	20	100	200	300	400	500	600	700	800	900
Steel density, pn, ^kg/m3	7720	7680							7440	7390
Heat transfer coefficient W/(m -°C)		15				22	24	25	27	29
Test temperature,°C	20−100	20−200	20−300	20−400	20−500	20−600	20−700	20−800	20−900	20−1000
Coefficient of linear expansion (a, 10−6 1/°C)	16.1					17.8	17.8	18.1	18.5	18.8

Steel 20X25H20C2