Astragalus membranaceus is a relatively precious medicinal material. Its use value is higher than that of white peony and licorice, and its market value is also very impressive. In recent years, the area of ​​cultivation of Astragalus membranaceus has continued to expand. In order to ensure the efficiency of planting, local scientific instruments such as agricultural meteorological recorders have been used to deepen meteorological services for agriculture, and precise meteorological services have been used to promote the development of Chinese herbal medicines such as Astragalus.
Huang Yuxi is warm and cold-resistant, drought-tolerant, and adaptable to the dry land in the sunny sun. However, the climatic environment in the open field cannot be completely matched with its needs, so to a large extent, the meteorological environment is One of the important factors affecting the quality of scutellaria planting. In order to reduce the bad impression of severe meteorological disasters, it is more and more necessary to enable meteorology to increase production and income for crops such as Astragalus and so on. It is increasingly necessary to use scientific instruments such as agricultural meteorological recorders to strengthen the monitoring of the agrometeorological environment.
In the process of planting and growing of Astragalus membranaceus, the use of agricultural meteorological recorders focuses on the detection and analysis of meteorological elements closely related to the growth of jaundice such as temperature, precipitation, sunshine and humidity. On the one hand, it can avoid risks, prevent prevention work in advance, and improve disaster resistance. The ability to prevent disasters, on the other hand, can guide scientific farming operations, such as choosing the right timing for planting, timing of irrigation, etc., to help the development of characteristic agriculture.
Astragalus planting is a highly valued planting project and one of the precise poverty alleviation projects in many areas. The use of agricultural meteorological recorders to ensure the safety of planting of Astragalus membranaceus and guide scientific production is not only the need for the healthy development of modern Chinese herbal medicine industry, but also an effective measure and method to improve management level and improve the quality of Chinese herbal medicine planting. Under its protection, the development of the Chinese herbal medicine planting industry has become smoother, the industrial value has become more prominent, and the goal of saving costs, increasing production and increasing efficiency has been achieved, making it truly a rich industry that can help farmers increase their income.
Tungsten carbide roller has characteristics of good wear resistance, high temperature red hardness, thermal fatigue resistance and thermal conductivity and high strength , have been widely used in high-speed wire rod, bar, rebar, seamless steel tubes, etc. Domestic production of tungsten carbide roller materials mostly WC- Co, WC- Co- Ni- Cr two series, and the content of Co, Co- Ni - Cr is in the range of 6wt% ~ 30wt%. From the use of perspective, tungsten carbide rollers has good mechanical properties, its flexural strength up to 2200 MPa or more, shock toughness up (4 ~ 6) × 10^6 J/ m^2, Rockwell hardness (HRA) is up to 78 to 90, widely in the high-speed wire rod rolling process, which is much higher than single-slot chilled cast steel or high speed steel rolls.Tungsten carbide is made of Tungsten Carbide Powder and binder phase (such as drilling, nickel, etc.), and then pressing and sintering, regardless of the conditions under cold rolled or hot rolled has excellent wear resistance, tungsten carbide rollers has been widely used in pre-finishing mill and finishing of high-speed wire rod currently. On the performance of tungsten carbide roller in hot-rolling wire rod , the material must meet the following requirements:
1. Sufficient anti-fracture strength;
2. Good abrasion resistance;
3. The smooth surface finish;
4. Excellent corrosion resistance, thermal fatigue, thermal cracking performance.
Tungsten carbide roller rings can working in bad conditions , small profile rolling (especially rebar rolling) process conditions is harsher than the high-speed wire rod, and therefore corresponds to the profile rolling ,tungsten carbide rollers recommend using high binder phase carbide.
Tungsten carbide roller material design
Pre-finishing all vehicles roller should ensure its high toughness, strength, rigidity and thermal conductivity, followed before considering its wear resistance. When designing each vehicles roller, pre-finishing materials should choose carbide grades of Co, Co- Ni- Cr binder content is high (greater than or equal to 25wt%) , requiring an average WC grain size of coarse (5μm ~ 6μm), to obtain a higher shock toughness, proper strength and hardness. For the finishing of the roller movements, particularly the last two rollers of the finish rolling, which suffered load is small, and high relative velocity of the material to be pressed (80 m / min ~ 120 m / min). In this case, the wear resistance of the roller to be the most important requirements, and must ensure the strength , timpact toughness and hardness of a reasonable match, so the binder of Co / Ni content ratio and the average grain WC control of particle size and other factors must have greater control in front of different pre-finishing rolling roll.
Tungsten carbide roller category
According to the structure of tungsten carbide rollers, it can be divided into solid tungsten carbide roller and composite tungsten carbide roller. Solid tungsten carbide rollers have been widely used in pre-finishing and finishing stands high speed wire rod mill (including fixed reducing the rack, pinch roller rack). Composite tungsten carbide roller is made of cemented carbide and other materials, and it can be divided into tungsten carbide composite roll rings and solid tungsten carbide composite roller. Tungsten carbide composite roll rings mounted on the roller shaft; solid tungsten carbide composite roller will be directly cast in the roll axis to form a whole, a large load is applied to the rolling mill.
Tungsten carbide roller production process control
Tungsten carbide rollers produced by powder metallurgy method, the key to its process control is the chemical composition of the material and the mixture was prepared, pressed molding, sintering and deep processing and other preparation process parameters.
1. Preparation of starting material (WC focus quality): As the WC raw material and quality control of the use of different levels of quality may fluctuate, resulting in adverse effects on microstructure.
2. Preparation of the mixture: Mixture preparation is the key to the production process of the roller, the roller of failure modes - trachoma, mainly generated by this procedure.
3. Pressing: roller pressing is an important process of the roller mill.
4. Sintering: roller sintering is to determine the final quality of the roller production processes, use of advanced low-pressure sintering technology, HIP sintering technology can greatly improve the performance of roller.
5. Deep processing: deep processing rollers have a greater impact on the quality and accuracy of the roller surface.
Carbide Roller,Carbide Ring,Mill of Rolling Line,Steel Wire Rod,Mill Rolling Finish Stand,Mill Roller Groove Type
Luoyang Golden Egret Geotools Co., Ltd , https://www.hvofpowders.com