Performance characteristics of W18Cr4V steel and microstructure of high speed steel
W18Cr4V steel is one of the most important tool materials in machining. It has high metal cutting performance (such as thermosetting and wear resistance), but its hardness is high, plasticity is low, forgeability is poor, mainly forging The deformation resistance is large, the forming is difficult, and it is prone to defects such as overheating, over-burning, cracks, and white spots. In the past few years, the forging of W18Cr4V cake-type milling cutters produced by our factory often has cracks in the forging process (in the actual production, metal ingots and steels of other materials also occur in the forging process during the forging process). This has resulted in varying levels of raw material waste and production losses. In particular, in recent years, companies have faced various difficulties (sufficient funds, shortage of raw materials, etc.), and conducted multi-party investigations and data collection, and conducted more thorough research on such issues. The promotion of the results will inevitably bring certain economic benefits to the production of the enterprise. 1. Performance characteristics and chemical composition The outstanding features of W18Cr4V steel are: high heat hardness, high strength, hardness and wear resistance. At the same time, it also has high hardenability. However, the plasticity is low, the toughness is poor, the deformation resistance is large, and the forgeability is poor. The chemical composition of W18Cr4V is shown in Table 1. The function of each alloying element is that W, V and Cr respectively form a composite carbide with C, so that the high speed tool steel maintains a high hardness at a relatively high temperature. W and V together create a thermosetting property, and the improvement of W and C greatly improves the wear resistance of steel. Cr increases the hardenability of steel, which together with W forms a composite carbide that prevents the accumulation of carbides at high temperatures. 2. High-speed steel organization The as-cast microstructure of high-speed tool steel usually consists of three forms of carbide: nascent carbide precipitated by liquid alloy, which is coarse fish bone (called Leysite), which has high brittleness and low plasticity; reticulated secondary carbide The mechanical properties of the material are reduced; finally, the finely uniformly dispersed eutectoid cubic carbide is precipitated by transformation from austenite to pearlite. These composite carbides are difficult to completely dissolve into austenite and cannot be dispersed by heat treatment. Only the crude primary carbide and another part of the secondary carbide can be crushed by forging and uniformly distributed by metal flow. . The high-speed tool steel is rolled into steel (this material is used to form a sheet-milling forging blank). Due to the different degree of deformation, the degree of carbide fracture (called carbide segregation) and distribution in the steel is also different. Due to the segregation of carbides and other factors, the defects of the as-cast microstructure cannot be completely eliminated in the steel structure after rolling, and further forging is required.
1. Impeller using the theory of ternary flow design, the application of flow analysis technology to predict the performance of the blower, the variable efficiency of up to 82%
2. See the machine using axial intake and diffuser adjustment device, the flow adjustment range of 45% of rated flow to 110%, so that it operates under non-rated conditions also have a higher efficiency
3. The assembled overall structure, the blower body assembled in the gear box gear box, lubricating oil system, motor and gear box compact layout on a common base, the base also serves as a fuel tank
4. Strict dynamic balance of the rotor, small vibration, high reliability, the overall low noise, low moment of inertia, start and stop the unit a short time, it is with the same flow and pressure multi-stage Centrifugal Fan, the energy consumption is small Light weight, small footprint
5 witnessed advanced and reasonable structure, wearing parts, installation, operation and maintenance convenience. The whole machine bearing vibration, temperature, anti-surge control, start the interlock protection, fault alarm, lubrication system oil pressure, oil temperature control, etc. are using programmable logic controller control, the machine running real-time monitoring
Technical indicators
Blower flow: 80 ~ 800m3 / min
Boost: 49 ~ 140kPa
The main purpose
This series of fans are widely used day power, chemical industry, iron and steel smelting, cement, pneumatic conveying, sewage treatment and other departments and industries, the transmission medium for the clean air
The pneumatic performance and structural design of the series of products reach the advanced level of similar products at home and abroad, with the advantages of energy saving, high efficiency, integration, high degree of automation, small size, light weight and high reliability, which can be widely used in sewage treatment, metallurgy, Circulating fluidized bed boiler fluidized power plant, gas desulfurization, pharmaceuticals, gas booster and other industries
Single Stage High Speed Centrifugal Blower Single Stage High Speed Centrifugal Blower,Single Stage Centrifugal Blower With High Efficiency Shenzhen Fu Sheng Electric Co., LTD. , http://www.fushengfan.com
For more details, please see the attached content or "Metal Processing (Hot Processing)" No. 19
