40KHFA steel is used: for the manufacture of improved splined shafts, rods, screws, cross-arms, shafts, excavators and other details, operating at temperatures up to +400 °C; after hardening and low tempering — for the production of worm shafts and other parts with increased wear resistance; after quenching in oil and tempering air for the production of parts of pipeline fittings.

Note

Structural steel high quality chrome vanadium.

Standards

Name	Code	Standards
Sheets and strips	В23	GOST 103-2006
Bars and shapes	В32	GOST 1051-73, GOST 4543-71, GOST 7417-75, GOST 8559-75, GOST 8560-78, GOST 14955-77, TU 3-1053-86, TU 14-1-1609-76, TU 14-1-2118-77, TU 14-1-950-74, TU 14-11-245-88, TU 14-1-5228-93, TU 14-136-367-2008
Bars and shapes	В22	GOST 1133-71, GOST 8319.0-75, GOST 2590-2006, GOST 2591-2006, GOST 2879-2006
Processing of metals by pressure. Forgings	В03	GOST 8479-70, TU 0306.018-80, ST ЦКБА 010-2004
Blanks. Of the workpiece. Slabs	В31	OST 3-1686-90, TU 14-1-4944-90, TU 1-92-156-90
Thermal and thermochemical treatment of metals	В04	ST ЦКБА 026-2005

Chemical composition

Standard	C	S	P	Mn	Cr	Si	Ni	Fe	Cu	V	Ti	Mo	W
TU 14-1-950-74	0.37-0.44	≤0.025	≤0.025	0.5-0.8	0.8-1.1	0.17-0.37	≤0.3	Rest	≤0.25	0.1-0.18	≤0.03	≤0.15	≤0.2
GOST 4543-71	0.37-0.44	≤0.025	≤0.025	0.5-0.8	0.8-1.1	0.17-0.37	≤0.3	Rest	≤0.3	0.1-0.18	≤0.03	≤0.15	≤0.2

Fe is the basis.
GOST 4543-71 regulates the content of high-quality steel: P≤0,025%; S≤0.015%; Сu≤0.25%.

Mechanical properties

Section, mm	t отпуска, °C	s_T\|s_0,2, MPa	σ_U, MPa	d₅, %	y, %	KCU, kJ/m²	HB, MPa	HRC
Forgings. Hardening + Vacation
100-300	-	≥395	≥615	≥15	≥40	≥530	187-229	-
300-500	-	≥395	≥615	≥13	≥35	≥481	187-229	-
100-300	-	≥490	≥655	≥13	≥40	≥530	212-248	-
≤100	-	≥540	≥685	≥15	≥45	≥579	223-262	-
100-300	-	≥540	≥685	≥13	≥40	≥481	223-263	-
Blank pieces of pipe fittings. Quenching in oil from 880-900 °C (exposure for 2.5-4.0 hours depending on the thickness and weight of the workpiece) with the following tempering in the air
≤100	670-700	≥540	≥685	≥15	≥45	≥588	223-262	-
Forgings. Hardening in water from 850 °C + vacation at 600 °C, air cooling (named place of clippings sample, samples, tangential)
160	-	≥710	≥850	≥16	≥44	≥470	-	-
Rolled steel. Quenching in oil from 850 °C + vacation, chilling after a holiday 500 °C in water
-	200	≥1490	≥1860	≥14	≥43	≥490	-	≥51
Rolled steel. Quenching in oil from 850 °C + vacation at 640 °C
-	-	≥840	≥920	≥26	≥63	-	-	-
Blank pieces of pipe fittings. Quenching in oil from 880-900 °C (exposure for 2.5-4.0 hours depending on the thickness and weight of the workpiece) with the following tempering in the air
≤300	680-700	≥440	≥635	≥14	≥40	≥539	197-235	-
Forgings. Hardening in water from 850 °C + vacation at 600 °C, air cooling (named place of clippings sample, samples, tangential)
200	-	≥510	≥800	≥18	≥49	≥470	-	-
Rolled steel. Quenching in oil from 850 °C + vacation, chilling after a holiday 500 °C in water
-	300	≥1450	≥1650	≥15	≥30	≥300	-	≥49
Rolled steel. Quenching in oil from 850 °C + vacation at 640 °C
-	-	≥800	≥900	≥22	≥46	-	-	-
Blank pieces of pipe fittings. Quenching in oil from 880-900 °C (exposure for 2.5-4.0 hours depending on the thickness and weight of the workpiece) with the following tempering in the air
≤60	660-680	≥640	≥785	≥15	≥42	≥588	248-293	-
Forgings. Hardening in water from 850 °C + vacation at 600 °C, air cooling (named place of clippings sample, samples, tangential)
240	-	≥570	≥770	≥19	≥50	≥540	-	-
Rolled steel. Quenching in oil from 850 °C + vacation, chilling after a holiday 500 °C in water
-	400	≥1270	≥1360	≥14	≥39	≥390	-	≥46
Rolled steel. Quenching in oil from 850 °C + vacation at 640 °C
-	-	≥740	≥840	≥18	≥35	-	-	-
Bars and strip hot rolled and forged. Quenching in oil with 865-895 °C + Vacation at 620-680 °C, cooling in water or oil
	-	≥735	≥880	≥10	≥50	≥880	269-320	-
Forgings. Hardening in water from 850 °C + vacation at 600 °C, air cooling (named place of clippings sample, samples, tangential)
240	-	≥700	≥830	≥17	≥49	≥610	-	-
Rolled steel. Quenching in oil from 850 °C + vacation, chilling after a holiday 500 °C in water
-	500	≥1100	≥1160	≥15	≥61	≥610	-	≥42
Rolled steel. Quenching in oil from 850 °C + vacation at 640 °C
-	-	≥710	≥850	≥28	≥50	-	-	-
Rolled steel. Quenching in oil with 860-880 °C + vacation at 200-230 °C, cooling in oil
≤40	-	≥1270	≥1570	-	≥35	≥383	-	49-53
Forgings. Hardening in water from 850 °C + vacation at 600 °C, air cooling (named place of clippings sample, samples, tangential)
120	-	≥710	≥860	≥12	≥37	≥640	-	-
Rolled steel. Quenching in oil from 850 °C + vacation, chilling after a holiday 500 °C in water
-	600	≥880	≥960	≥19	≥98	≥980	-	≥34
Rolled steel. Quenching in oil from 850 °C + vacation at 640 °C
-	-	≥400	≥490	≥30	≥65	-	-	-
Forgings. Hardening in water from 850 °C + vacation at 600 °C, air cooling (named place of clippings sample, samples, tangential)
160	-	≥610	≥830	≥15	≥46	≥450	-	-
Rolled steel. Quenching in oil from 850 °C + vacation at 640 °C
-	-	-	≥370	≥51	≥80	-	-	-
Forgings. Hardening in water from 850 °C + vacation at 600 °C, air cooling (named place of clippings sample, samples, tangential)
200	-	≥490	≥710	≥17	≥49	≥570	-	-
240	-	≥490	≥710	≥18	≥51	≥710	-	-
50	-	≥900	≥940	≥15	≥45	≥690	-	-
80	-	≥810	≥890	≥11	≥33	≥390	-	-

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)

Physical characteristics

Temperature	Е, HPa	G, HPa	r, kg/m³	l, W/(m · °C)	a, 10^-6 1/°C	С, J/(kg · °C)
0	215	84	7810	37	-	-
20	215	-	7810	37	-	-
100	212	83	-	37	121	466
200	205	80	-	37	126	508
300	199	77	-	36	13	529
400	182	71	-	33	133	563
500	173	66	-	31	138	592
600	166	64	-	31	142	621
700	144	56	-	30	146	634
800	135	52	-	28	146	634
1000	-	-	-	-	118	664

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	Steel difficult weldability. Welding methods: RDS - necessary heating and subsequent heat treatment. CCC - a necessary subsequent heat treatment.
Склонность к отпускной хрупкости	Inclined.
The temperature of forging	Start - 1250 °C, the end - 860 °C-800. Cross sections up to 200 mm are cooled in mulde, 201-300 mm - with oven.
Flock-sensitive sensitivity	Sensitive.
Machinability	After quenching and tempering at НВ241 and Kn TV.SPL.=A 0.75 Kn b.St.=0,65.

Steel 40KHFA (40ХФ)

Designation

Description