Steel 25KH1MF (ЭИ10)

Designation

Name	The value
Designation GOST Cyrillic	25Х1МФ
Designation GOST Latin	25X1MF
Transliteration	25H1MF
By chemical elements	25Cr1MoV

Name	The value
Designation GOST Cyrillic	ЭИ10
Designation GOST Latin	EI10
Transliteration	EhI10
By chemical elements	-

Description

25KH1MF steel is used: for the manufacture of bolts, flat springs, pins and other parts operating at temperatures up to +510 °C; mounting parts operating at temperatures from -40 °C to +500 °C; fasteners of nuclear power plants; pipelines with quenching in oil and tempering air; fasteners turbines and flange connections, steam pipelines and valves by cold machining and hot forming, operating at a steam temperature +500−580 °C.

Note

Steel parlingo class.
Temperature intense scaling +600 °C.

Standards

Name	Code	Standards
Sheets and strips	В23	GOST 103-2006
Bars and shapes	В22	GOST 1133-71, GOST 2590-2006, GOST 2591-2006
Sheets and strips	В33	GOST 4405-75
Bars and shapes	В32	GOST 7417-75, GOST 8559-75, GOST 8560-78, GOST 14955-77, GOST 20072-74, TU 14-1-1397-75, TU 14-1-5037-91, TU 14-1-552-72, TU 14-11-245-88
Thermal and thermochemical treatment of metals	В04	ST ЦКБА 026-2005
Processing of metals by pressure. Forgings	В03	TU 0306.018-80, ST ЦКБА 010-2004

Chemical composition

Standard	C	S	P	Mn	Cr	Si	Ni	Fe	Cu	V	Ti	Mo	W
TU 14-1-552-72	0.22-0.29	≤0.025	≤0.03	0.4-0.7	1.5-1.8	0.17-0.37	≤0.25	Rest	≤0.3	0.15-0.3	-	0.25-0.35	-
GOST 20072-74	0.22-0.29	≤0.025	≤0.03	0.4-0.7	1.5-1.8	0.17-0.37	≤0.3	Rest	≤0.02	0.15-0.3	≤0.03	0.25-0.35	≤0.2

Fe is the basis.
According to GOST 20072-74 steel grade 25X1MF can be manufactured with a mass fraction of molybdenum in the range of 0.6-0.8%, in this case it is designated 25X1M1F (P2). When smelting steel with scrap-process, the content of Cu ≤ 0.30%. Tungsten is allowed up to 0.20%, titanium up to 0.030%. When smelting steel by the method of electroslag remelting, the mass fraction of sulfur should not be more than 0.015%.

Mechanical properties

Section, mm	t отпуска, °C	s_T\|s_0,2, MPa	σ_U, MPa	d₅, %	y, %	KCU, kJ/m²	HB, MPa
Blank pieces of pipe fittings. Quenching in oil from 940-960 °C (exposure for 2.5-4.5 hours depending on the thickness and weight of the workpiece) with the following tempering in the air
≤150	640-660	675-785	≥813	≥16	≥50	≥600	269-311
Forgings. Quenching in oil from 860 °C to + Vacation at 515 °C, air cooling
≤250	-	≥780	≥930	≥10	≥40	≥490	285-321
Rolled steel. Quenching in oil with 910-920 °C + Vacation
-	540	≥1220	≥1270	≥13	≥58	-	-
Rolled steel. Quenching in oil with 930-950 °C + Vacation at 620-660 °C
-	-	790-1000	880-1050	16-19	60-64	-	-
Normalization at 1000 °C, air cooling + Vacation at 650 °C, the cooling air (provided the temperature and duration of heat exposure)
-	-	≥800	≥970	≥15	≥52	-	-
Blank pieces of pipe fittings. Quenching in oil from 940-960 °C (exposure for 2.5-4.5 hours depending on the thickness and weight of the workpiece) with the following tempering in the air
≤200	660-680	590-675	≥735	≥16	≥50	≥600	235-272
Forgings. Quenching in oil from 860 °C to + Vacation at 515 °C, air cooling
250-350	-	≥690	≥860	≥12	≥45	≥590	269-302
Rolled steel. Quenching in oil with 910-920 °C + Vacation
-	570	≥1190	≥1230	≥16	≥61	-	-
Rolled steel. Quenching in oil with 930-950 °C + Vacation at 620-660 °C
-	-	≥610	≥710	≥17	≥68	-	-
Normalization at 1000 °C, air cooling + Vacation at 650 °C, the cooling air (provided the temperature and duration of heat exposure)
-	-	≥870	≥980	≥15	≥60	-	-
Forgings. Quenching in oil with 930-950 °C + Vacation at 620-660 °C, air cooling
20-180	-	≥665	≥780	≥16	≥50	≥590	-
Forgings. Quenching in oil from 860 °C to + Vacation at 515 °C, air cooling
350-450	-	≥590	≥780	≥14	≥45	≥590	241-277
Rolled steel. Quenching in oil with 910-920 °C + Vacation
-	600	≥1150	≥1190	≥18	≥61	-	-
Rolled steel. Quenching in oil with 930-950 °C + Vacation at 620-660 °C
-	-	≥590	≥690	≥17	≥71	-	-
Rolled steel. Quenching in oil from 950 °C to + Vacation at 620 °C (indicated by temperature and duration of heat exposure)
-	-	≥940	≥1110	≥18	≥61	-	-
Bars hot rolled and forged (12-180 mm). Quenching in oil with 930-950 °C + vacation at 620-660 °C, air cooling
	-	≥670	≥780	≥16	≥50	≥590	-
Rolled steel. Quenching in oil with 910-920 °C + Vacation
-	630	≥1060	≥1120	≥19	≥62	-	-
Rolled steel. Quenching in oil with 930-950 °C + Vacation at 620-660 °C
-	-	≥580	≥620	≥19	≥75	-	-
Rolled steel. Quenching in oil from 950 °C to + Vacation at 620 °C (indicated by temperature and duration of heat exposure)
-	-	≥990	≥1160	≥17	≥55	-	-
Rolled steel. Quenching in oil with 880-900 °C + Vacation at 640-660 °C, air cooling
25	-	≥735	≥880	≥14	≥50	≥590	-
Rolled steel. Quenching in oil with 910-920 °C + Vacation
-	660	≥880	≥960	≥19	≥69	-	-
Rolled steel. Quenching in oil with 930-950 °C + Vacation at 620-660 °C
-	-	≥490	≥550	≥20	≥78	-	-
Rolled steel. Quenching in oil from 950 °C to + Vacation at 620 °C (indicated by temperature and duration of heat exposure)
-	-	≥980	≥1090	≥18	≥60	-	-
Rolled steel. Normalizing at 1,000 °C + Vacation at 650 °C
	-	810-870	940-980	≥17	51-58	-	-
Rolled steel. The annealing at 920 °C
-	-	≥400	≥540	≥24	≥75	-	-
Rolled steel. Quenching in oil from 950 °C to + Vacation at 620 °C (indicated by temperature and duration of heat exposure)
-	-	≥950	≥1070	≥17	≥60	-	-
Rolled steel. The annealing at 920 °C
-	-	≥260	≥380	≥23	≥79	-	-
-	-	≥240	≥330	≥24	≥82	-	-

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	G, HPa	r, kg/m³	l, W/(m · °C)	R, Mr. · m	a, 10^-6 1/°C	С, J/(kg · °C)
0	213	82	7840	-	-	-	-
20	217	-	7840	-	-	-	-
100	207	80	-	40	312	113	462
200	204	77	7790	39	396	117	-
300	194	75	-	38	475	128	462
400	187	71	7720	37	574	139	-
500	176	66	-	36	680	142	-
600	164	63	7650	35	826	142	-
800	-	-	-	-	-	144	-

A description of the physical symbols

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

Technological properties

Name	The value
Weldability	Difficult weldability. Welding methods: RDS and ADS.
Склонность к отпускной хрупкости	tend not
The temperature of forging	Start - 1180 °C, the end - 850 °C. the cross Sections up to 60 mm are cooled in stacks in the air, 61-200 mm are subjected to low temperature annealing.
Flock-sensitive sensitivity	Sensitive.
Machinability	In the normalized and tempered condition in NV ?300 Kn TV.SPL.=0,70 Kn b.St.=0,25.