Steel 20kp
Description
Steel 20kp
Steel 20kp: brand of steels and alloys. Below is a systematized information on the purpose, chemical composition, types of supplies, substitutes, temperature of critical points, physical, mechanical, technological and casting properties for the grade — Steel 20kp.
General information of steel 20kp
| Substitute brand |
| steel 15kp |
| Delivery type |
| Long products, including shaped: GOST 2590−71, GOST 2879−69, GOST 19772−74, GOST 19771−74, GOST 8278−75, GOST 8281−80, GOST 8282−83, GOST 8283−77, GOST 10702 -78. Calibrated bar GOST 7417−75, GOST 8560−78, GOST 10702−78. Polished bar and silver bar GOST 14955−77, GOST 10702−78. Thick sheet GOST 19903−74, GOST 4041−71, GOST 1577−81. Thin sheet GOST 19903−74, GOST 16523−70, GOST 19904−74. Tape GOST 10234−77. Strip GOST 82−70, GOST 103−76, GOST 1577−81. Wire GOST 17305−71, GOST 2771−81, GOST 3282−74, GOST 5663−79. Pipes GOST 10705−80, GOST 10704−91. |
| Application |
| Without heat treatment or after normalization — pipes, fittings, plugs, bolts, flanges, apparatus bodies and other parts made of boiling steel, operating from -20 to 425 ° C; after carburizing and cyanidation — parts that require high surface hardness and low core strength (axles, fasteners, pins, sprockets, etc.). |
Chemical composition of steel 20kp
| Chemical element |
% |
| Silicon (Si), no more |
0.07 |
| Manganese (Mn) |
0.25−0.50 |
| Copper (Cu), no more |
0.25 |
| Arsenic (As), no more |
0.08 |
| Nickel (Ni), no more |
0.25 |
| Sulfur (S), no more |
0.040 |
| Carbon (C) |
0.17−0.24 |
| Phosphorus (P), no more |
0.035 |
| Chromium (Cr), no more |
0.25 |
Mechanical properties of steel 20kp
| Heat treatment, delivery condition |
σ B, MPa |
δ 5 ,% |
ψ,% |
HB |
| Calibrated and calibrated steel with special finishing after annealing or tempering |
390−490 |
|
50 |
163 |
| Calibrated and calibrated steel with special finishing after spheroidizing annealing |
345−440 |
|
50 |
163 |
| Steel calibrated and calibrated with a special finish, work-hardened without heat treatment |
490 |
7 |
45 |
197 |
| Normalized or hot rolled strips |
380 |
27 |
55 |
|
| Heat-treated sheets of the 1st-2nd category |
345−490 |
28 |
|
127 |
Mechanical properties of steel after HTT
| Section, mm |
σ 0.2, MPa |
σ B, MPa |
δ 5 ,% |
ψ,% |
KCU, J / m 2 |
HB |
HRC e |
| Cementation 920−950 ° C, quenching 800−820 ° C, water, tempering 180−200 ° C, air. |
| 50 |
295 |
490 |
sixteen |
40 |
49 |
156 |
55−63 |
Technological properties of steel 20kp
| Forging temperature |
| Beginning 1280, end 750. Air cooling. |
| Weldability |
| It can be welded without restrictions (except for HTO parts). Welding methods: RDS, ADS submerged arc and gas shielded, KTS. |
| Machinability by cutting |
| In hot-rolled condition at HB 130 K υ tv.spl. = 1.7 and K υ b.st. = 1.6. |
| Tendency to release ability |
| not inclined |
| Flock sensitivity |
| not sensitive |
Temperature of critical points of steel 20kp
| Critical point |
° C |
| Ac1 |
735 |
| Ac3 |
850 |
| Ar3 |
835 |
| Ar1 |
680 |
Impact strength of steel 20kp
Impact strength, KCU, J / cm 2
| Delivery status, heat treatment |
+20 |
-20 |
-40 |
-60 |
| Strip 12 mm thick. Quenching, tempering |
257 |
200−223 |
170−304 |
174 |
| Strip 12 mm thick. Normalization, vacation |
225−230 |
131−180 |
127−147 |
9−80 |
| Strip 12 mm thick. Annealing |
132−143 |
41 |
fifteen |
fifteen |
Physical properties of steel 20kp
| Test temperature, ° С |
20 |
100 |
200 |
300 |
400 |
500 |
600 |
700 |
800 |
900 |
| Normal elastic modulus, E, GPa |
212 |
208 |
203 |
197 |
189 |
177 |
163 |
140 |
|
|
| Density of steel, pn, kg / m 3 |
|
7834 |
7803 |
7770 |
7736 |
7599 |
7659 |
7617 |
7624 |
7600 |
| Thermal conductivity coefficient W / (m ° С) |
|
51 |
49 |
44 |
43 |
39 |
36 |
32 |
26 |
26 |
| Test temperature, ° С |
20−100 |
20−200 |
20−300 |
20−400 |
20−500 |
20−600 |
20−700 |
20−800 |
20−900 |
20−1000 |
| Linear expansion coefficient (a, 10−6 1 / ° С) |
12.3 |
13.1 |
13.8 |
14.3 |
14.8 |
15.1 |
15.2 |
|
|
|
