On the same day, at the round table, the US embassy in China embassy 阮 Dawei, the US embassy business official Han Bo韬, Xi’an alien office deputy director Qiang Sheng, Xi’an Transportation Bureau deputy director Li Binke, Cummins ’s group vice president Cao 德de, Shaanxi Automobile Group Chairman Yuan Hongming, General Manager Xi'an Bus Co., Ltd. Lou Changwei, Xi'an Jinlong Chairman Liu Xiaobin, Cummins General Manager of China Natural Gas and Bus Market Liu Yue, Xi'an Cummins Engine Co., Ltd. General Manager Yang Xiaodong, and Allison, Wood Ward and other officials and business representatives from both China and the United States in the public transport field. Facilitating Climate Change Through Technical Cooperation In the face of the global crisis of resources, energy, and environment, countries around the world are actively transitioning to low carbon and developing green economies. In order to promote cooperation between China and the U.S. in clean technology for public transportation and provide more clean and efficient solutions for the local public transport sector, the U.S. Embassy’s Commercial Office unites several leading U.S. companies in the Midwest of China. The city actively communicates and promotes the widespread use of clean technology in public transportation. In his speech, the U.S. Ambassador to China stated in his speech that China and the United States have always worked very hard in terms of climate change. At the recent G20 Hangzhou summit, China and the United States jointly announced the ratification of the Paris Agreement for Climate Change. It has assumed the responsibility for energy conservation and emission reduction and promised to contribute to global climate change. “Now, apart from the plans and initiatives made by the government, the Sino-US industry and companies need to cooperate in the research and development of new technologies to solve the problem of fuel economy and technological development of heavy trucks or passenger cars, allowing more new technologies to enter the market. Application areas to further reduce emissions and make efforts for climate change." In this regard, Yuan Hongming stated in his speech that Shaanxi Automobile Group has advantages in terms of natural gas technology in both trucks and passenger cars. In the future development, it also hopes to have more extensive cooperation with the United States in public transport clean technology. . It is understood that China is vigorously expanding the use of clean energy, especially natural gas power. This has greatly increased the demand for natural gas and natural gas engines, especially in urban public transport and public transportation systems that connect the suburbs and urban areas. At the same time, China is actively increasing investment in the extraction of natural gas and building the necessary infrastructure to promote the West-East Gas Transmission. This has created conditions for the promotion of natural gas power. Focus on natural gas power Cummins' "quasi-zero emissions" technology has great potential for environmental protection At the Sino-U.S. roundtable meeting, Cao Side, vice president of Cummins Inc. Group, introduced the new generation of Near Zero technology in the United States and explained the environmental protection potential of traditional energy and alternative energy sources. With Smart Efficiency, Cummins not only achieved near-zero emissions reduction, but also achieved new breakthroughs in improving power efficiency and energy efficiency. This not only provides a highly efficient, economical and promising future technology route for new models, but also guides the direction of numerous in-use vehicle upgrades. Emissions from European and American markets have always been a barometer of global concern, and the "zero emissions" technology line is the focus of European and American research. It is understood that natural gas is inherently superior to traditional energy sources in the reduction of nitrogen oxide emissions, and it has strong commonality with diesel engine platforms, and it has an advantage in terms of design and manufacturing costs. "Cummins Near Zero's zero-emissions emissions' use of natural gas power is low, and its low-carbon characteristics are unmatched. In addition, the industry continues to develop renewable energy, such as through the traditional process of waste and food waste processing to obtain biomass energy. The total emissions of the vehicle during its entire life cycle are expected to be further reduced,†Cao Side said in his speech. Cummins has been in China for 40 years and has been committed to introducing the most advanced product platform to China. Among them, Cummins is a pioneer in the use of alternative energy engines for public transportation. This application of clean energy has unique advantages in reducing greenhouse gas emissions. "Especially natural gas engines, they are the best choice for urban public transportation system energy conservation and environmental protection." Cao Side said that Cummins's goal is very clear, that is, to provide environmentally friendly and efficient products and technologies, not only to meet emission requirements and greenhouse gas emission reduction requirements. And it has excellent performance, reliability, durability, strong power, high fuel efficiency, and low operating costs. In the next 5-10 years or even longer, vehicle energy will continue to develop in the direction of diversification and low carbonization. There will still be a strong demand for the development of clean, environmentally friendly, economical, and safe clean vehicles. Advanced and efficient Diesel and gas-powered technologies are relatively mature and have formed a certain industrial base. Cummins will be committed to promoting clean and efficient development of its engines. Through the integration of innovations with vehicle companies, it will further improve its power efficiency and reduce its carbon footprint on the premise of meeting various pollutant discharge standards.
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:
Tungsten carbide roller material design
Tungsten carbide roller category
Tungsten carbide roller production process control 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.xtcalloypowder.com
A photo of representatives from the China-US public transport clean technology round table 
U.S. Embassy in China Gives Speeches 
Deputy Director of Xi’an Alien Office Qiang Sheng 
Shaanxi Automobile Group Chairman Yuan Hongming spoke 
Cao Side, vice president of Cummins Group, spoke
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.
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.
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 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.
Cummins: Natural Gas Power "Quasi-Zero Emissions" Technology Has Big Potential for Environmental Protection
On September 27, 2016, the Sino-U.S. public transport clean technology roundtable with the theme of "Smart and Efficient Greening the Future" was held in Xi'an. The conference was initiated by the Commerce Department of the U.S. Embassy in China and has conducted a series of exchanges and promotion with the Chinese side on the wide application of clean technologies in the public transportation field between China and the United States. The first stop was placed in the ancient capital of Xi'an. The organizer of the Chinese side was Xi'an Foreign Affairs Office.