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	s_T\|s_0,2, MPa	σ_U, 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
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
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.