In the hot summer, because of special factors such as high temperature and rainy summer, and people’s poor mental health, we must ensure the safety of high-altitude aerial vehicles and high-altitude operations. The following eight aspects must attract attention. The specifics can be summarized as “two guaranteesâ€. , "two not", "two defenses", "two mo" four "two".
Two guarantees: First, to ensure a good night's sleep. Summer is long, people go to bed late, driving during the day is very easy to be trapped. Especially at noon, often feel sleepy and blind. At this time, the high-altitude truck driver is best to rest for a while, Or wash your face with cold water, move your limbs, wait for energy recovery, keep your head awake and continue driving to ensure traffic safety. The second is to maintain the normal state of mind. High summer temperatures, the driver's emotional instability, a slight disobedience on the "fire". The operator of the vehicle must adjust and control his own bad feelings and maintain a normal state of mind. He can put some music in his train to adjust his emotions.
Two is not: First, the "disease car" is not on the road. Summer heat, heavy rain on all parts of the aerial work vehicle is a severe test. Water tank "open pot" on the road, the engine "sticky cylinder", on fire, puncture The circuit is very short circuited by moisture. Therefore, before you hit the road, you'd better check the brakes, water tanks, tires, etc. of the car to prevent unpleasant things happening on the road. The second is without inflammables. The car is parked under the hot sun. Don't put lighters, cola, etc. in the car, especially on the dashboard.
Two defenses: First, sunny days against "virtual light." Summer asphalt roads are prone to "virtual light" after exposure to the sun, need to carefully identify the road, correct judgments, in order to ensure the safety of driving, high-altitude truck drivers can wear light-colored sunglasses, To reduce the direct sunlight, but not to wear dark glasses too dark, the dark color of the sunglasses can delay the time the eyes send the image to the brain. This visual delay also causes the speed to feel distorted, making you make a wrong judgment, especially the speed When it is high, dark sunglasses will prolong your response time to the situation. Second, it is anti-skid in the rainy weather. There is much rain in the summer. High-altitude truck drivers must slow down when they encounter heavy rain during the journey, maintaining adequate safety with pedestrians and vehicles. Distance, should not rush to hit the steering wheel, so as to avoid accidents caused by sliding.
Two Mo: First, wear a pair of slippers to drive the car. Many high-altitude truck drivers like to wear slippers to drive in the summer, in fact, it is very dangerous. Second, open the air conditioning Mo sleep. In the car space is not airtight Next, if air-conditioners are turned on for a long time while the aerial vehicle is stopped, it will cause air in the vehicle to be difficult to convection. The carbon monoxide produced by the engine's operation may gather in the car, and the carbon dioxide that the passengers breathe will be emitted over a long period of time. Poisoning
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.xtcthermalspray.com