Sep 13 2012
Topics Covered
IntroductionChemical CompositionPhysical PropertiesMechanical PropertiesOther Designations
Introduction
High-speed tool steels are of two types, namely molybdenum high-speed steels and tungsten high-speed steels. The molybdenum high-speed steels are also referred to as Group M steels. In the United States, 95% or more of all manufactured high-speed steels are the Group M steels. The high-speed tool steel types have equal performance but the molybdenum high-speed steels have relatively lower initial cost. To enhance performance and tool service life, tools made of high-speed tool steel can be coated with titanium carbide, titanium nitride, and other coatings using the physical vapor deposition process.
There are many types of molybdenum high-speed steels. The following data sheet will provide details relating to M34 molybdenum high-speed steel.
Chemical Composition
The following table shows the chemical composition of M34 steels.
| Element |
Content (%) |
| C |
0.85-0.92 |
| Mn |
0.15-0.40 |
| Si |
0.20-0.45 |
| Cr |
3.50-4.00 |
| Ni |
0.3 |
| Mo |
7.75-9.20 |
| W |
1.40-2.10 |
| V |
1.90-2.30 |
| Co |
7.75-8.75 |
| Cu |
0.25 |
| P |
0.03 |
| S |
0.03 |
Physical Properties
The physical properties of M34 steels are outlined in the following table.
| Physical properties |
Conditions |
| T (°C) |
Treatment |
| Density |
7.7-8.03 x 1000 kg/m3 |
25 |
- |
Mechanical Properties
The mechanical properties of M34 steels are tabulated below.
| Mechanical properties |
Conditions |
| T (°C) |
Treatment |
| Poisson's ratio |
0.27-0.30 |
25 |
- |
| Elastic modulus |
27557-30458 ksi |
25 |
- |
Other Designations
Other designations that are equivalent to AISI M34 molybdenum high-speed tool steels include:
- DIN 1.3249
- B.S. BM 34
- ASTM A600
- FED QQ-T-590
- UNS T11334