Steel 20KH

Designation

Name The value
Designation GOST Cyrillic 20Х
Designation GOST Latin 20X
Transliteration 20H
By chemical elements 20Cr

Description

20X steel is used: for the manufacture of hot rolled plates; bushings, gears, collars, sleeves, drives, plungers, levers and other case hardening of parts, which required high surface hardness with a low strength of the core; parts operating in conditions of wear and friction; parts of pipeline fittings from rolled steel; forged blanks and forgings (requires heat treatment: quenching in water and tempering air).

Note

Steel structural quality chrome.

Standards

Name Code Standards
Bars and shapes В32 GOST 1051-73, GOST 4543-71, GOST 7417-75, GOST 8559-75, GOST 8560-78, GOST 10702-78, GOST 14955-77, TU 14-1-5414-2001, TU 14-1-2118-77, TU 14-1-3238-81, TU 14-11-245-88, TU 14-1-3238-2006, TU 14-1-1271-75, TU 14-1-5228-93, TU 14-136-367-2008
Sheets and strips В33 GOST 1577-93, TU 14-1-1035-74, TU 14-1-1409-75, TU 14-1-1579-75, TU 14-1-2506-78, TU 14-1-4118-86, TU 14-1-4118-2004
Sheets and strips В23 GOST 82-70, GOST 19903-74, GOST 103-2006, GOST 19903-90
Bars and shapes В22 GOST 8278-83, GOST 8281-80, GOST 8282-83, GOST 8283-93, GOST 8319.0-75, GOST 9234-74, GOST 11474-76, GOST 2590-2006, GOST 2591-2006, GOST 2879-2006
Processing of metals by pressure. Forgings В03 GOST 8479-70, OST 5Р.9125-84, ST ЦКБА 010-2004
Steel pipes and fittings to them В62 GOST 8732-78, GOST 8734-75, GOST 9567-75, GOST 23270-89, GOST 24950-81, GOST 8733-87, GOST 8731-87, GOST Р 53383-2009, TU 14-3-473-76, TU 14-3-1654-89
Welding and cutting metals. Soldering, riveting В05 OST 26-17-017-85
Blanks. Of the workpiece. Slabs В31 OST 3-1686-90, TU 14-1-4944-90
Thermal and thermochemical treatment of metals В04 ST ЦКБА 026-2005
Tape В34 TU 3-326-86, TU 14-4-1389-86, TU 14-4-795-77

Chemical composition

Standard C S P Mn Cr Si Ni Fe Cu V Ti Mo W
TU 14-1-3238-81 0.17-0.23 ≤0.03 ≤0.03 0.5-0.8 0.7-1 0.17-0.37 ≤0.3 Rest ≤0.3 ≤0.05 ≤0.03 ≤0.15 ≤0.2
GOST 10702-78 0.17-0.23 ≤0.035 ≤0.035 ≤0.6 0.7-1 ≤0.2 ≤0.3 Rest ≤0.3 ≤0.05 ≤0.03 ≤0.15 ≤0.2
Fe is the basis.
According to GOST 4543-71 the content in high-quality steel is regulated: P≤0,025%; S≤0.025%; Сu≤0.30%; in high-grade steel: P≤0,025%; S≤0.015%; Сu≤0.25%. In accordance with the order, the content of Si = 0.10-0.37%, Mn = 0.4-0.8% can be established.
According to TU 14-1-3238-81, the chemical composition is given for steel grade 20ХА. For steel grade 20ХА-СШ the content S≤0.015%.

Mechanical properties

Section, mm t отпуска, °C sT|s0,2, MPa σU, MPa d5, % y, % KCU, kJ/m2 HB, MPa HRC
Steel calibrated and calibrated with special surface finish
- - - ≥590 ≥5 - ≥45 ≤207 -
- - - ≤550 - - ≥60 ≤179 -
- - - 360-470 - - ≥60 ≤179 -
Forgings. Hardening + Vacation
100-300 - ≥245 ≥470 ≥19 ≥42 ≥383 143-179 -
100-300 - ≥275 ≥530 ≥17 ≥38 ≥333 156-197 -
100 - ≥275 ≥530 ≥20 ≥40 ≥432 156-197 -
100-300 - ≥315 ≥570 ≥14 ≥35 ≥333 167-207 -
100-300 - ≥345 ≥590 ≥17 ≥40 ≥530 174-217 -
Forgings. Normalization
100-300 - ≥195 ≥390 ≥23 ≥50 ≥530 111-156 -
300-500 - ≥195 ≥390 ≥20 ≥45 ≥481 111-156 -
100 - ≥195 ≥390 ≥26 ≥55 ≥579 111-156 -
100-300 - ≥215 ≥430 ≥20 ≥48 ≥481 123-167 -
100 - ≥215 ≥430 ≥24 ≥53 ≥530 123-167 -
100 - ≥245 ≥470 ≥22 ≥48 ≥481 143-179 -
Seamless hot deformed tubes in the delivery condition
- - ≥431 ≥16 - - - -
Blank pieces of pipe armature. Quenching in water from 880-900 °C (exposure for 2.5-4.0 hours, depending on the thickness and weight of the workpiece) + Vacation, air cooling
80 500-560 ≥345 ≥590 ≥16 ≥45 ≥588 174-217 -
Hot-rolled steel and hot rolled with special surface heat-treated
- - - - - - ≤163 -
A rod with a diameter of 25 mm. Quenching in oil from 900 °C + Vacation
- 200 ≥650 ≥880 ≥18 ≥58 - - -
A sample with a diameter of 6 mm, length 30 mm forged and normalized. The rate of deformation of 16 mm/min strain Rate of 0.009 1/s
- - ≥120 ≥150 ≥48 ≥89 - - -
Long products (wire). Quenching in water or oil at 880 °C + Quenching in water or oil with 770-820 °C + Vacation at 180 °C, cooling in air or oil
≤15 - ≥635 ≥780 ≥11 ≥40 ≥579 - -
A rod with a diameter of 25 mm. Quenching in oil from 900 °C + Vacation
- 300 ≥690 ≥880 ≥16 ≥65 - - -
A sample with a diameter of 6 mm, length 30 mm forged and normalized. The rate of deformation of 16 mm/min strain Rate of 0.009 1/s
- - ≥63 ≥93 ≥56 ≥74 - - -
Long products (wire). Cementation at 920-950 °C, air cooling + Quenching in oil from 800 °C + Vacation at 190 °C, air cooling
40-60 - ≥390 ≥640 ≥13 ≥40 ≥481 ≥250 55-63
A rod with a diameter of 25 mm. Quenching in oil from 900 °C + Vacation
- 400 ≥690 ≥850 ≥18 ≥70 - - -
A sample with a diameter of 6 mm, length 30 mm forged and normalized. The rate of deformation of 16 mm/min strain Rate of 0.009 1/s
- - ≥51 ≥84 ≥64 ≥88 - - -
A rod with a diameter of 25 mm. Quenching in oil from 900 °C + Vacation
- 500 ≥670 ≥780 ≥20 ≥71 - - -
A sample with a diameter of 6 mm, length 30 mm forged and normalized. The rate of deformation of 16 mm/min strain Rate of 0.009 1/s
- - ≥33 ≥51 ≥78 ≥97 - - -
Seamless cold-worked tubes in the delivery condition heat-treated (NV - wall > 10 mm)
- - ≥431 ≥17 - - ≤179 -
A rod with a diameter of 25 mm. Quenching in oil from 900 °C + Vacation
- 600 ≥610 ≥730 ≥20 ≥70 - - -
A sample with a diameter of 6 mm, length 30 mm forged and normalized. The rate of deformation of 16 mm/min strain Rate of 0.009 1/s
- - ≥21 ≥33 ≥98 ≥100 - - -
- - ≥14 ≥25 - - - - -

Description mechanical marks

Name Description
sT|s0,2 Yield strength or limit of proportionality with a tolerance for residual deformation of 0.2%
σU 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)
0 216 84 7830 42 - -
100 213 83 7810 42 105 496
200 198 76 7780 41 116 508
300 193 74 - 40 124 525
400 181 71 7710 38 131 537
800 133 50 - 31 14 626

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 Welded without restriction (except chemical-thermally treated parts). Welding methods: SMAW, CCC.
Склонность к отпускной хрупкости Tend not.
The temperature of forging Start - 1260 °C, the end - 760 °C. of the Workpiece cross-section up to 200 mm are cooled in air, 201-700 mm are subjected to low temperature annealing.
Flock-sensitive sensitivity Insensitive.