China steelmanufacturing industry is the basic industry of national equipment manufacturing, especially the manufacturing of large China steel casting parts. Its development level is an important symbol to measure a country’s comprehensive national strength. China steel casting parts are mainly divided into three categories: carbon steel, low alloy steel and high alloy steel. Among them, carbon steel castings refer to China steel casting parts with carbon as the main alloy element and a small amount of other elements. They have high strength, plasticity and toughness and are mainly used to manufacture structural parts bearing large load in heavy machinery; Low alloy steel castings refer to China steel casting parts containing silicon, manganese, chromium, copper and other alloy elements. The total amount of alloy elements is generally less than 5%, with large impact toughness and better mechanical properties than carbon steel. They are mainly used for structural parts and wear-resistant parts bearing large load; High alloy steel castings refer to alloy steel castings refined to meet special needs. They usually contain one or more alloy elements with a total content of more than 10% to obtain some special properties, such as high chromium nickel such as steam turbine shell of power generation equipment, gas turbine cylinder block and water turbine runner.
At present, China has been able to independently produce key China steel casting parts widely used in power station, petrochemical industry, metallurgy, mining, rail transit, shipbuilding, national defense and military industry, agricultural machinery, engineering machinery and other equipment manufacturing industries. For example, the runner and blade of large water turbine unit, stainless steel main pump body in nuclear power equipment, steam turbine and gas turbine, wind power and large engine cylinder block, clamp and leading hook of high-speed EMU, rolling mill frame and roll in large metallurgical equipment, rudder arm of large ship, large bearing pedestal, end cover,ring and lining plate of large ball mill have high quality requirements Large China steel casting parts with complex technology. It has the casting technology of organizing 900 tons of molten steel at one time, pouring 520 tons of China steel casting parts, 450 tons of high-quality China steel casting parts, 180 tons of stainless steel castings and large gear ring China steel casting parts with a diameter of more than 10 meters. Recently, the steel casting workshop of Dongfang Steam Turbine Co., Ltd. successfully poured the stainless steel castings of high and intermediate pressure outer cylinder of 600000 kW thermal power turbine with the largest tonnage in China, with a single piece weight of 51 tons and nearly 90 tons of molten steel.
Many enterprises are developing high-end castings such as heavy castings, nuclear power castings, thermal power supercritical high and medium pressure steam cylinders, large hydropower stainless steel castings, high-end alloy steel castings of the Three Gorges ship lift, marine thrusters, marine castings and so on. And began to transform from the original large and all-round to specialized and refined, with the gradual improvement of the degree of specialization, the formation of their own characteristic products, and the continuous improvement of domestic and international influence; For example, the nuclear power castings developed by the first heavy, the nuclear power and thermal power castings of the second heavy, the hydropower stainless steel castings of Ningxia share and Anshan Iron and steel machinery general, the heavy large metallurgical and rolling forging equipment castings, the mine castings produced by CITIC Heavy Industry, the thermal power, hydropower and wind power castings of Dalian Huarui, the heavy marine China steel casting parts, etc.
The production capacity of China steel casting parts has been continuously improved, the casting output has increased year by year, and the quality of China steel casting parts has been steadily improved. According to incomplete statistics of China Foundry Association, China casting output has achieved positive growth for 15 consecutive years except 2015, from 13.26 million tons in 2002 to 47.2 million tons in 2016. China casting capacity has increased by 190.3% in 15 years, and the casting output has ranked first in the world for 10 consecutive years. The output of steel casting parts in China has accounted for 10-13% of the total castings. From 2002 to 2014, China steel casting parts output has achieved positive growth for 13 consecutive years. In 2014, China casting output reached the highest value of 5.5 million tons. Affected by the manufacturing environment in 2015 and 2016, China steel casting parts output decreased, but remained stable at 5.1 million tons. In 2016, China total imports and exports of various castings were 15000 tons and 1873000 tons, a decrease of 24000 tons and 71000 tons respectively compared with 17400 tons and 1944000 tons in 2015. In 2016, the average export price of China castings was US $1338.2/t, a decrease of 9.8% over US $1484 / T in 2015, and the average import price of castings was US $7573 / T, an increase of US $359 / t over US $7214 / T in 2015.
It can be seen that there is still a large gap in the quality and performance of China high-end castings compared with developed countries, which is difficult to meet the needs of the domestic market and depends on imports. With the development of China equipment manufacturing industry and the improvement of manufacturing technology, the quality of high-end China steel casting parts and the total output of castings will continue to improve. It is estimated that during the 13th Five Year Plan period, the growth rate of China casting output will remain within 4%. By 2020, the annual output of China castings will reach about 55 million tons, the output value of castings will reach about 700 billion yuan, and the casting quality will be significantly improved.