Steel 20kp

Designation

Name The value
Designation GOST Cyrillic 20кп
Designation GOST Latin 20kp
Transliteration 20kp
By chemical elements 20

Description

Steel 20kp used: for the manufacture of sheet metal, 1−2 mm 4−14 category, intended for cold forming without heat treatment or after normalization, nipples, fittings, plugs, bolts, flanges, housings vessels and devices operating under low pressure and at temperatures from -20 °C to +425 °C, after carburizing and cyanidation parts, which require high surface hardness and low strength of the core (axles, fasteners, fingers, stars); electric-welded pipes.

Note

The degree of deoxidation — KP.

Standards

Name Code Standards
Tape В34 GOST 10234-77, GOST 19851-74
Bars and shapes В32 GOST 1050-88, GOST 7417-75, GOST 8560-78, GOST 10702-78, GOST 14955-77, GOST 1050-2013, TU 14-1-2118-77, TU 14-11-245-88, TU 14-1-1271-75, TU 14-136-367-2008
Sheets and strips В33 GOST 1577-93, GOST 4041-71, TU 14-1-4516-88
Classification, nomenclature and General rules В70 GOST 2771-81
Steel pipes and fittings to them В62 GOST 3262-75, GOST 10704-91, GOST 10705-80, GOST 10707-80, TU 14-3-1428-86, TU 1373-022-05757850-08, TU 1373-013-02949352-2003
Low carbon steel wire В71 GOST 3282-74, GOST 5663-79
Tape В24 GOST 3560-73
Steel wire medium and high carbon В72 GOST 3920-70, GOST 7372-79, GOST 9389-75, GOST 9850-72, GOST 17305-91, GOST 26366-84
Sheets and strips В23 GOST 82-70, GOST 14918-80, GOST 16523-97, GOST 19904-90, 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 10551-75, GOST 11474-76, GOST 19771-93, GOST 19772-93, GOST 2590-2006, GOST 2879-2006
Blanks. Of the workpiece. Slabs В31 OST 3-1686-90, TU 14-1-4944-90

Chemical composition

Standard C S P Mn Cr Si Ni Fe Cu N As
GOST 1050-88 0.17-0.24 ≤0.04 ≤0.035 0.25-0.5 ≤0.25 ≤0.07 ≤0.3 Rest ≤0.3 ≤0.006 ≤0.08
Fe is the basis.
According to GOST 1050-88, the nitrogen content is specified for the steel of the oxygen-converter method of smelting. For all other types of smelting, the nitrogen content was N≤0.008%.

Mechanical properties

Section, mm sT|s0,2, MPa σU, MPa d5, % d4 d d10 y, % KCU, kJ/m2 HB, MPa HRC HRB
Tape flatted average strength of 0.1-4.0 mm according to GOST 10234-77 in the state of delivery (indicated delivery)
- - 490-830 - - - - - - - - -
- - 390-540 - - - - - - - - -
- - 540-690 - - - - - - - - -
- - 690-830 - - - - - - - - -
- - ≤540 - - ≥15 - - - - - -
- - ≤410 - - - - - - - - -
Rolled sheet 1-2 categories of heat-treated (annealing, normalization, high tempering or normalizing + tempering) in the delivery state according to GOST 4041-71
4-14 - 340-490 ≥28 - - ≥24 - - ≤127 - ≤71
Wire for cold heading as supplied by GOST 5663-79
- - 470-620 - - - - ≥55 - - - -
- - ≤640 - - - - ≥50 - - - -
Longitudinal electric-welded pipes (Dy=10-530 mm) in the delivery condition. Listed marsvolta base metal
- ≥225 ≥372 ≥22 - - - - - - - -
Hot-rolled steel and hot rolled with special surface finish
- - - - - - - - - ≤156 - -
- - - - - - - - - ≤132 - -
Steel calibrated and calibrated with special surface finish
- - ≥490 ≥7 - - - ≥45 - ≤197 - -
- - 390-490 - - - - ≥50 - ≤163 - -
- - 340-440 - - - - ≥50 - ≤163 - -
Leaves heat-treated 1 and 2nd categories
- - 345-490 ≥28 - - - - - ≤157 - -
Hot-rolled sheet in the delivery condition. Group strength К330В
≤2 - 330-460 - ≥23 - - - - - - ≤73
2-3.9 - 330-460 - ≥24 - - - - - - ≤73
Cold-rolled sheet in the delivery condition. Group strength К330В
≤2 - 330-460 - ≥24 - - - - - - ≤73
2-3.9 - 330-460 - ≥25 - - - - - - ≤73
Strip. After normalizing or hot rolled
- - ≥380 ≥27 - - - ≥55 - - - -
Cementation at 920-950 °C + quenching in water from 800-820 °C + vacation at 180-200 °C, air cooling
50 ≥295 ≥490 ≥16 - - - ≥40 ≥481 ≥156 55-63 -

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
d4 Elongation after rupture
d Elongation after rupture
d10 Elongation after rupture
y The relative narrowing
KCU Toughness
HB Brinell hardness number
HRC Rockwell hardness (indenter diamond spheroconical)
HRB Rockwell hardness (indenter steel, spherical)

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 - - - - -
20 212 - - - - -
100 208 7834 51 219 123 486
200 203 7803 49 292 131 498
300 197 7770 44 381 138 514
400 189 7736 43 487 143 533
500 177 7599 39 601 148 555
600 163 7659 36 758 151 584
700 140 7617 32 925 151 636
800 - 7624 26 1094 - 703
900 - 7600 26 1135 152 703
1000 - - - - - 695

A description of the physical symbols

Name Description
Е The normal elasticity modulus
r Density
l Coefficient of thermal conductivity
R UD. the resistivity
a The coefficient of linear expansion
С Specific heat

Technological properties

Name The value
Weldability Welded without restriction (except XTO). Welding methods: SMAW, ADS submerged arc and gas protection, the CCC.
Склонность к отпускной хрупкости Tend not.
The temperature of forging Start - 1280 °C, the end - 750 °C. air Cooling.
Flock-sensitive sensitivity not sensitive.
Machinability In the hot rolled condition with HB of 130 Kn TV.SPL.=1,7 Kn b.St.=1,6.