Designation by Standards
| Brand Name |
Ravne No. |
Mat. No. |
DIN |
EN |
AISI |
| CT781 |
781 |
1.6587 |
17CrNiMo6 |
17CrNiMo7 |
4820 |
Chemical Composition (in weight %)
| C |
Si |
Mn |
Cr |
Mo |
Ni |
V |
W |
Others |
| 0.18 |
max.0.40 |
0.70 |
1.65 |
0.30 |
1.55 |
- |
- |
- |
Description
Nickel-molybdenum alloy steel. Alloyed case hardening steel for heavy and high strained gear parts with high demands on toughness at core tensile strength of 1050-1350 N/mm
2.
Applications
Severely stressed components for mechanical engineering and automobile industry.
Physical properties (avarage values) at ambient temperature
Modulus of elasticity [10
3 x N/mm
2]: 210
Density [g/cm
3]: 7.87
Thermal conductivity [W/m.K]: 38.0
Electric resistivity [Ohm mm
2/m]: 0.18
Specific heat capacity[J/g.K]: 0.46
Coefficient of Linear Thermal Expansion 10-6 oC-1
| 20-100oC |
20-200oC |
20-300oC |
20-400oC |
20-500oC |
| 11.2 |
12.1 |
12.9 |
13.4 |
13.9 |
Continuous Cooling Transformation (CCT) Diagram
Click the image to enlarge the diagram.
Time-Temperature Transformation (TTT) Diagram
Click the image to enlarge the diagram.
Soft Annealing
Heat to 650-700
oC, cool slowly in furnace. This will produce a maximum Brinell hardness of 229.
Intermediate Annealing: 630-650
oC.
Hardening
Carburising: 880-980
oC.
Core Hardening: 830-870
oC, water.
Case Hardening: 780-820
oC, water.
Normalizing
Normalizing: 850-880
oC, air.
Tempering
Tempering temperature: 150-200
oC.
Soft annealed treated: max. 229 HB.
Treated for cold shearability: max. 255 HB.
Treated for strength: max. 229 HB.
Treated for ferite and pearlite structure and hardness range: 159-207 HB.
Tensile Strength Rm in N/mm2 vs. Diameter in mm
After Hardening and Tempering at 200oC
| Diamter in mm |
d<=16 |
17<d<=40 |
41<d<=100 |
| Tensile Strength Rm in N/mm2 |
min. 1200 |
min. 1100 |
min. 900 |
Hardenability Diagram
Click the image to enlarge the diagram.
Forging
Hot forming temperature: 1050-850
oC.
Machinability
No data.
Forms manufactured: Please see the
Dimensional Sales Program.
Disclaimer
The information and data presented herein are typical or average values and are not a guarantee of maximum or minimum values. Applications specifically suggested for material described herein are made solely for the purpose of illustration to enable the reader to make his own evaluation and are not intended as warranties, either express or implied, of fitness for these or other puposes. There is no representation that the recipient of this literature will receive updated editions as the become available.
Unless otherwise specified, registered trademarks are property of Metal Ravne company. Copyright 2011 by Metal Ravne. All rights reserved.
Contact our
Sales Office for more information.
