1.7027, 20Cr4, 5120, 20Ch – case-hardening steel according to ISO 683-17:2014 i GOST 4543-71.
Table of content:
| Standard | Grade | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chemical composition % | |||||||||||||||
| C: | Si: | Mn: | P: | S: | Cr: | Ni: | Cu: | ||||||||
| PN | 20H | ||||||||||||||
| 0.17-0.23 | 0.17-0.37 | 0.5-0.8 | <0.035 | <0.035 | 0.7-1.0 | <0.3 | - | ||||||||
| ISO | 1.7027 | ||||||||||||||
| 0.17-0.23 | <0.4 | 0.6-0.9 | <0.025 | <0.030 | 0.9-1.2 | - | <0.3 | ||||||||
| GOST | 20Ch - 20H | ||||||||||||||
| 0.17-0.23 | 0.17-0.37 | 0.5-0.8 | <0.035 | <0.035 | 0.7-1.0 | <0.3 | <0.3 | ||||||||
| ISO | 20Cr4 | ||||||||||||||
| 0.17-0.23 | 0.15-0.40 | 0.6-0.9 | <0.035 | <0.035 | 0.9-1.2 | - | - | ||||||||
| AISI | 5120 | ||||||||||||||
| 0.13-0.18 | 0.15-0.35 | 0.7-0.9 | <0.035 | <0.040 | 0.7-0.9 | - | - | ||||||||
20H, 1.7027, 20Cr4, 5120, 20Ch – description
Steel used for small parts with higher strength requirements than 15Cr3 steel, e.g. spindles, pins, camshafts and bushings. Weldable, machinable and cuttable steel. Weld only before carburizing.
Physical and mechanical properties
Here You can find the mechanical properties of selected alloys. Despite their similarities, they clearly differ.
| Properties | Grade | ||||
|---|---|---|---|---|---|
| PN | ISO | GOST | ISO | ||
| 20H | 20Cr4 | 20Ch | 1.7027 | ||
| Yield strength: | Rm | > 640 MPa | > 850 MPa | > 637 MPa | - |
| Tensile strength: | Rm | > 780 MPa | 820-1170 MPa | > 784 MPa | - |
| Wydłużenie: | A5 | 11 % | 9 % | 11 % | - |
| Udarność KCU, 20°C: | KCU2 J/cm2 | 60 J/cm2 | KU: 25J/cm2 | 59J/cm2 | - |
| Twardość po odprężaniu: | HB | < 179 HB | < 197 HB | < 179 HB | < 197 HB |
Mechanical properties after hardening:
- Diameter D: 11 mm
- Tensile strength Rm: 820-1170 MPa
- Yield strength Re: min 550 MPa
- Elongation A: min 9 %
- Impact Value KU: min 25 J
- Diameter D: 30 mm
- Tensile strength Rm: 750-1100 MPa
- Yield strength Re: min 490 MPa
- Elongation A: min 9 %
- Impact Value KU: min 25 J
- Diameter D: 63 mm
- Tensile strength Rm: 670-1020 MPa
- Yield strength Re: min 450 MPa
- Elongation A: min 10 %
- Impact Value KU: min 25 J
Heat treatment and plastic working
Following parameters are recommended for working and heat treatment
| Treatment | Grade | ||||
|---|---|---|---|---|---|
| PN | ISO | GOST | ISO | ||
| 20H | 20Cr4 | 20Ch | 1.7027 | ||
| Quenching | Temperature | 880℃ | 860-900℃ | 880℃ | 860-900℃ |
| Cooling | oil, water | - | oil, water | - | |
| Tempering | Temperature | 180℃ | 150-200℃ | 180℃ | 150-200℃ |
| Cooling | air, oil | - | air, oil | - | |
We deliver this steel alloy as:
- Bars, strips and reels
- Rods
- Wires
- Plates
Replacements, equivalents and other designations:
20H, 20Ch, 20Ch-Sh, 20Cr, 1.7027, 20Cr4, SCr22, SCr420, B21, 5120, C41201, 20Ch-PV