24 July 2021 High Speed Steel Bar
W9Mo3Cr4V High Speed Steel Bar
W9Mo3Cr4V high-speed steel is a general-purpose tungsten-molybdenum high-speed steel with medium content of tungsten, adding a small amount of molybdenum, and appropriately controlling the content of carbon and vanadium to achieve the purpose of improving performance, improving quality, and saving alloying elements.
The metallurgical quality and process performance of W9Mo3Cr4V high-speed steel (hereinafter referred to as W9) have both the advantages of W18Cr4V high speed steel (abbreviated as W18) and W6Mo5Cr4V2 steel (abbreviated as W6), and avoid or significantly reduce the main shortcomings of the two. This is a general-purpose new steel grade that meets my country's resources and production conditions and has good comprehensive performance. W9Mo3Cr4V high-speed steel is easy to smelt, has good thermal and cold plasticity, high yield, carbide distribution characteristics are better than W18 high-speed steel, similar to M2 high-speed steel , decarburization sensitivity is lower than M2 high-speed steel, production cost is higher than W18 and M2 Low. Due to the good thermal and cold plasticity of the steel, it can meet the requirements of the machine manufacturer using multiple upsetting and forging, high-frequency plus thermoplastic forming processes and cold stamping processes.
W9Mo3Cr4V high-speed steel has good cutting performance, better grinding performance and weldability than M2 high-speed steel, and lower heat treatment sensitivity to overheating than M2. The main mechanical properties of steel: hardness and red hardness level are equivalent to or slightly higher than W18 and M2; strength and toughness are higher than W18 and comparable to M2: machine saw blades, drill bits, broaches, hobs, milling cutters made The service life of tools such as, taps and other tools is higher than that of W18, which is equal to or higher than the service life of M2, and the service life of gear shaper cutters is equivalent to that of M2. The rolling thread rolling wheel made of W9Mo3Cr4V high-speed steel has achieved remarkable results when rolling high-temperature alloys. After appropriately changing the quenching and tempering process, W9Mo3Cr4V high-speed steel is also very suitable for manufacturing high-load molds, especially cold extrusion molds.
Chemical Composition:
| C(％) | Si(％) | Mn(％) | P(％) | S(％) | Cr(％) | Ni(％) | Cu(％) | V(％) | Mo(％) | W(%) |
|---|---|---|---|---|---|---|---|---|---|---|
| 0.77～0.87 | 0.20 ~ 0.40 | 0.20 ~ 0.40 | ≤0.030 | ≤0.030 | 3.80～4.40 | ≤0.30 | ≤0.25 | 1.30 ~ 1.70 | 2.70 ~ 3.30 | 8.50 ~ 9.50 |
Mechanical Propoerties:
| Yield Strength Rp0.2(MPa) | Tensile Strength Rm(MPa) | Impact Energy KV(J) | Elongation at Fracture A(%) | Impact toughness value αkv (J/cm2) | Hardness |
|---|---|---|---|---|---|
| ≥ 1920(110) | ≥ 2080(120) | ≥ 98 | ≥ 9 | ≥ 60 | ≥ 64 HRC |
Physical properties:
Critical point | Ac1 | Ac3 |
|---|---|---|
Temperature (approximate value)/℃ | 835 | 875 |
Table 2-30-3 Elastic modulus of W9Mo3Cr4V steel
Temperature/℃ | Room temperature | 300 | 500 | 550 | 600 |
|---|---|---|---|---|---|
Elastic modulus E/MPa | 221900 | 209000 | 191600 | 185,000 | 178600 |
Table 2-30-4 Linear (expansion) coefficient of expansion of W9Mo3Cr4V steel
Temperature/℃ | 20～300 | 20～500 | 20～700 |
|---|---|---|---|
Linear (expansion) coefficient of expansion (annealed state)/℃-1 | 12.0×10-6 | 12.6×10-6 | 13.2×10-6 |
Table 2-30-5 Thermal conductivity of W9Mo3Cr4V steel
Temperature/℃ | 600 | 750 | 1100 |
|---|---|---|---|
Thermal conductivity λ/W·(m·k)-1 | 30.9 | 32.6 | 31.4 |
Thermal processing:
| Steel ingot forging billet | Furnace loading temperature/℃ | Heating temperature/℃ | Forging temperature/℃ | Final forging temperature/℃ | cool down | |
|---|---|---|---|---|---|---|
| 700 | 1160～1190 | 1080～1120 | ≥950 | Timely annealing or sand cooling | ||
| Hot rolled | Used blank size/mm | Heating temperature/℃ | heating time | Rolling temperature/℃ | Final rolling temperature/℃ | cool down |
| 80 square Φ40 | 1100～1150 1080～1120 | 2h30min～3h 15～25min | 1090～1120 1050～1100 | ≥900 ≥900 | Annealing after slow cooling Annealing after slow cooling |
Quenching specification:
Tool type | Preheating temperature/℃ | Heating temperature/℃ | Cooling method/℃ |
|---|---|---|---|
Machine saw blade Broach drill Hob, shaper cutter Rolling wheel Mould | 850 850 850 850 850 850 | 1240～1250 1220～1230 1220～1230 1230～1235 1180～1190 1160～1200 | Oil cooler Oil cooler Oil cooler Oil cooler 550 graded quenching Oil cooler |
Heat treatment:
Quenching, preheating at 820～870℃, heating at 1210～1230℃ (salt bath furnace) or 1220～1240℃ (box furnace), oil cooling, tempering twice at 540～560℃, 2h each time.