Development Status of Thermal Spraying in my country

       The world's thermal spraying has a history of 100 years, and China's thermal spraying has a history of nearly 50 years. Especially in the past two decades, China's thermal spraying has made great progress and development. The following is a brief introduction to the overall level and status, equipment and materials, applications, scientific research and development.

   1. Overall level and status According to incomplete statistics, during the "Eighth Five-Year Plan" period (1991-1995 including 1996), the total output value of China's thermal spraying industry was about 300 million yuan per year (including thermal spraying equipment, materials, construction and technology). services, auxiliary equipment materials, etc.). In 1996, the total output value of my country's national economy was about 7.5 trillion yuan (about 910 billion US dollars), and the output value of thermal spraying accounted for about 0.39/10000>. According to the statistics of the association, there are about 3,000 thermal spraying practitioners in the country (excluding temporary workers in the construction team), and 300 to 350 units engaged in thermal spraying work, including thermal spraying equipment, materials, auxiliary machines, auxiliary materials production plants, thermal spraying Construction and technical service units, as well as scientific research, teaching, development units and trading companies engaged in thermal spraying.

   Thermal spraying enterprises are still dominated by small units (<30 persons), accounting for more than 90% of the total. The per capita output value of the thermal spraying industry is about 100,000 yuan per person per year, which is a leader in the machinery industry (upper level).

   According to relevant foreign materials, in recent years, the total output value of thermal spraying in the United States is about 2 billion US dollars, and Japan is 80 billion yen, accounting for 3.6/10000 and 2.3/10000 of its gross national economic output (GNP) respectively. The ratio of thermal spraying production value to GNP weight is an important symbol of whether the country's thermal spraying is developed or not. This ratio in China is only 11% of that of the United States and 17% of that of Japan. This shows that China's thermal spraying is still in the development stage, far from reaching the mature and saturated stage. Because of this, thermal spraying has a vast market in China, with many opportunities and promising development prospects.

   2. After decades of independent development and introduction of thermal spraying equipment and materials, and drawing on foreign advanced technology, at present, China has been able to develop and produce vacuum plasma, atmospheric plasma, explosive spraying, plasma surfacing, arc spraying, flame powder spraying, Flame wire spraying equipment, producing metal powder (Ni, Co, Fe based, total about 300t/year), ceramic, cermet powder (Al2O3, Al2O3+TiO2, Cr2O3, WC-Co, etc., total about 200t/year), wire Materials (Al, Zn, Cu, stainless steel, etc., total about 1000t/year). Although the overall level of equipment is still not high, and there are still some quality problems in materials, China has become one of the few countries in the world that can be self-sufficient in thermal spray equipment and materials, basically meeting the needs of the thermal spray industry. . Meanwhile, about 10% of equipment and materials still need to be imported.

   3. Application of thermal spraying technology At present, thermal spraying technology has been widely used in China, the main application fields are aviation, aerospace, steel, petrochemical, steel structure anticorrosion, machinery, light industry, textile, paper, energy, shipbuilding etc., the total output value is about 200 million yuan / year. my country's thermal spray application has the following characteristics:

   ⑴ Wide range of applications, with a fairly high level in some fields, such as aero-engines (cooperation with Boeing), bottom rolls of annealing furnaces, galvanized guide rolls (steel industry), valves (petrochemical industry), wire drawing guide rolls, towers Wheels, wire drawing rings, etc. (textile industry), high-grade glass molds (light industry), valves (automotive industry), etc.

   (2) The techniques and materials used are extensive. Almost all thermal spraying techniques and materials currently used internationally are used in China, such as vacuum plasma spraying, atmospheric plasma spraying, explosive spraying, supersonic flame spraying, arc spraying, flame powder spraying, plasma spraying Surfacing, laser remelting, vacuum (protective atmosphere) remelting, etc.

   (3) The enterprises engaged in thermal spray application (Job Shop) are mainly small and medium-sized enterprises (<30 people), the number of people accounts for 2/3 of the total, and the output value accounts for more than 75% of the total output value. Joint-stock cooperative enterprises, private enterprises and collective enterprises account for a considerable proportion, and joint ventures and sole proprietorships have begun to appear.

   ⑷ The use of thermal spraying as a maintenance method for equipment and components is relatively developed. For medium and small thermal spraying enterprises, more than half of the work is for repair.

   ⑸ Relevant professional research offices and teaching and research offices of scientific research institutes, colleges and universities, such as welding (more than half), materials, surface processing and other majors, actively enter the domestic thermal spraying market. The main technical force of thermal spraying in my country is also in the above-mentioned units.

   At present, the main problems in application are that the scale is small, the level is uneven, and there is a lack of unified management and standards, and it is impossible to form leading thermal spraying enterprises with influence at home and abroad (such as Tocal in Japan, Praxair in the United States, and Praxair in France). SNMI, etc.).