copper alloys Overview
Copper alloy valves are used for water, seawater, oxygen, air, oil and other media with a nominal pressure less than or equal to PN25. Generally, they are used for low-to-medium valves and small-bore gas cylinder valves at normal temperature and high pressure. Copper has good plasticity and low temperature resistance, but its strength is low, and low-pressure valves with a temperature ≧ 196ºC can be used. The selection of a suitable copper alloy grade can also be used for oxygen pipeline valves with a working pressure ≦ 3.0 MPa, but copper is not resistant to ammonia corrosion and will cause corrosion or contamination of some chemical products. Therefore, some valves for chemical products are forbidden to use Copper internal parts and even external parts are not allowed to be made of copper.
Copper is the earliest metal material found and used by humans. Copper has a low melting point and is easy to alloy. It is one of the oldest metals used by humans. Humans have known natural copper as early as 7000 BC, about 3000 BC A high level of copper smelting has emerged around the world. 3500 years ago, people began to use copper alloys to make living utensils, which once created a splendid ancient bronze civilization. Modern industrial civilization products, most of which use metal materials, especially important parts, show its reliability, but the use of a single metal is rare, mostly using alloy materials, alloy varieties, manufacturing processes have their own characteristics. The characteristics of copper and copper alloys are not simply strength. They are mainly good in electrical conductivity and electrical conductivity. They must give full play to their good electrical conductivity to make the greatest contribution to society. In modern times, especially the industrial revolution of the 17th century, and the discovery of Faraday's law of electromagnetic induction, copper and copper alloys have excellent electrical conductivity, thermal conductivity, and corrosion resistance, are easy to process, and have attractive appearances. They have been widely used in modern engineering technology. , Widely used in machinery, electronics, electrical, chemical, transportation, energy, construction, information and communication fields, such as: an average copper 31 铜 for a tractor, an average copper 21㎏ for a liberated car, various household electrical appliances, Industrial installations are inseparable from copper and copper alloy products, which are irreplaceable important engineering materials in the national economy. According to foreign statistics, the consumption ratio of copper, copper alloys and steel in developed countries is about 1.3: 100. The variety and consumption of copper and copper alloys have become one of the indicators to measure a country's industrial technology level.
The fundamental feature of copper and copper alloys widely used in the field of engineering technology is that they are currently economical conductive materials. Pure copper has high electrical conductivity, thermal conductivity, suitable strength, and excellent corrosion resistance, second only to silver. It is easy to solder and deform. It is widely used in the manufacture of various electrical wires and conductors. The proportion of industry applications accounts for more than half of the total output, for example: manufacturing 10,000 kilowatts of power generation equipment, including nearly 800 tons of copper materials including power transmission and transformation equipment. In recent years, with the increasing urgency of energy resources, energy conservation and consumption reduction in various industries have become increasingly prominent. Electric motors are widely used and consume large amounts of electricity. Countries have attached great importance to the development and promotion of high-efficiency energy-saving motors. Among them, the important way to reduce resistance consumption is to increase the motor winding Cross-sectional area. At the same time, with the improvement of people's living standards, the civilian load has continued to increase, and the cross-sectional areas of various transmission cables have also increased. With the introduction of building codes such as copper-based aluminum and international standard configuration of residents' wire diameters, all are copper. Provides broad development prospects in the electrical field.
Another feature of copper and copper alloys is that they have excellent alloying properties and can form unique alloys with most current metal or non-metal elements. At present, more than 250 alloy grades have been formed, with nearly 10,000 specifications. Product series to meet the needs of various industries, and most of the copper alloys have strong corrosion resistance, for example: white copper has excellent mechanical properties, processing properties and corrosion resistance, suitable for high temperature and high pressure corrosion resistance environment, Widely used in medical, instrumentation, shipbuilding, chemical and other fields; tin bronze has excellent elasticity and high mechanical properties, and is widely used in the manufacture of elastic components and bearing friction sleeves in various instruments and meters; aluminum bronze has Compared with steel, it has high strength and excellent corrosion resistance, and is widely used in manufacturing various heavy-duty wear-resistant parts. With the development of modern science and technology, especially with the rapid development of information technology, new types of alloys used in the field of high and new technology continue to emerge, representing the development direction of contemporary engineering materials and has broad development prospects. At the same time, copper and copper alloys are currently the best environmentally friendly materials. Copper alloys used in various devices can be completely recovered and recycled. Recycled copper can maintain its original superior properties, which is unmatched by other recycled materials. Under the situation of relatively short copper resources in China, making full use of recycled copper resources has become an emerging industry. At present, with the increase in the production of electronic products and automobiles, the demand for copper processed products with excellent electrical conductivity and thermal conductivity has continued to increase, and products have become thinner and mass-produced, especially for the precision and flatness of lead frames, terminals and connector strips. The requirements for straightness, surface roughness, gloss, and discoloration prevention are getting higher and higher.