EN9 CARBON STEEL |070M55 BS970 STANDARD
EN9 Carbon steel is a medium carbon steel with 0.5-0.6% C as per BS 970 standard.It is also known as 070M55 with tensile strength between 500-800Mpa.
EN9 steel is generally supplied in untreated condition or in the normalized condition.This material can be flame or induction hardened to produce a high surface hardness with excellent wear resistance .When hardened and tempered, it develops a tensile strength in the range 700-1000 N/mm depending on ruling section.
EN9 Steel Steel Chemical Composition
| Grade | C | Si | Mn | P | S | |
| BS970-1955 | EN9 | 0.5-0.6 | 0.05-0.35 | 0.5-0.8 | ≤0.06 | ≤0.06 |
| BS970-1991 | 070M55 | 0.5-0.6 | 0.1-0.4 | 0.5-0.9 | ≤0.05 | ≤0.05 |
EN9 Steel Related Specifications
- BS 970-1991:070M55
- AISI/ASTM A29:1045,1050,1055,1060
- DIN Werkstoff No.: 1.0535,1.1209
- BS & DIN European:C45, CK45,C50,C55,CK55
- JIS G4051: S45C, S50C,S55C
EN9 Steel Heat Treatment & Mechanical Property
- Forging:1100℃-1200℃,cool in sand or furnace cool.
- Normalizing:820℃-880℃,Cool in air
- Annealing: 770-810ºC,Cool in furnace
- Quenching:810℃-840℃,oil quench
- Tempering:550°C – 660°C, cool in still air
EN9 Steel Mechanical Property in Normalized and Quenched & Tempered Conditon
Condition | Normalized | Quenched & Tempered |
||
| N | R | S | T | |
| Ruling Section,inch | 4 | 2 | 1 1/8 | 1 1/8 |
| Tensile Strength,Mpa | ≥695 | ≥695 | ≥775 | ≥850 |
| Yield Strength,Mpa | ≥355 | ≥465 | ≥510 | ≥555 |
| Elongation | ≥18% | ≥18% | ≥18% | ≥15% |
| Hardness,HBW | 201-255 | 201-255 | 223-277 | 248-302 |
EN9 Round steel Lab Tesing Data with Normalizing condition
| Diameter,mm | Tensile Strength MPa | Yield Strength MPa | Elongation % | Hardness,HB |
| Φ360 | 780 | 405 | 20 | 139-172 |
| Φ430 | 765 | 400 | 22 | 184-203 |
| Φ510 | 755 | 400 | 23 | 193-240 |
| Φ600 | 740 | 410 | 22 | 184-232 |
EN9 Steel Quality Certification
A material test report(Inspection Certificate EN 10204 3.1) will be provided, documenting the following:
1.Chemical analysis
2.Mechanical properties
3.Surface hardness
4.Non Metallic Inclusion
5.Heat Treatment Process
6.Grain size
7.Forging ratio
8.Ultrasonic test report
EN9 Steel Supply Form & Size &Surface Finish&Tolerance
| Form of Supply | Size(mm) | Length(mm) |
| Round bar | Φ6-Φ1,000 | 3,000-10,000 |
| Square bar | 100x100-600x600 | 3,000-6,000 |
| Plate/Sheet | Thickness :20-400 Width:80-1,000 | 2,000-6,000 |
| Flat bar/Blcoks | Thickness :120-800 Width:120-1,500 | 2,000-6,000 |
| Surface Finish | Black-Forged | Black-Rolled | Turned | Grinding | Polished | Peeled | Cold Drawn |
| Tolerance | (0，+5mm) | (0，+1mm) | (0，+3mm) | Best h9 | Best h11 | Best H11 | Best H11 |
Heat treatment:Quenched and Tempered (+QT), Normalizing (+N), Annealing (+A)
