Fushun Special Steel revealed that in mid-May, the company successfully completed the smelting of the heavy-duty turbine turbo wheel and the 100mm diameter GH4706 superalloy "triptych", and the composition control and surface quality of the alloy ingots met the technical requirements.
It is reported that the national scientific research project led by China Heavy Combustion Corporation Fushun Special Steel, Steel Research Gaona, Erzhong Wanhang and other units jointly set up, its diameter and weight level of high-temperature alloy production represents the highest level in the world today, the project standards are very high, to break through the large-size specifications of high-temperature alloy smelting, forging blank, die forging molding three "world-class" manufacturing problems.
The successful smelting of the large-size specification GH4706 "triptych" ingot marks that the national heavy-duty gas turbine turbine turbine turbot scientific research project has made significant progress, and also marks that Fushun Special Steel has reached the world's advanced level in the smelting technology of high-temperature alloy with extra-large size specifications.
It is worth mentioning that triple melting involves vacuum induction smelting (parent alloy), electroslag remelting (removal of phosphorus, sulfur, etc.), vacuum self-consumption (removal of nitrogen, hydrogen, oxygen, carbon, etc.), a considerable part of which is related to vacuum. It can be said that vacuum technology plays a crucial role in this.
In the metallurgical industry, the application of vacuum is not limited to this, but also to the list. For example, vacuum distillation, vacuum separation of ore and its semi-products, vacuum reduction of metal compounds, vacuum degassing and refining outside the molten steel furnace, metal vacuum casting, vacuum sintering, vacuum heat treatment, vacuum brazing and vacuum solid bonding and other process methods. Since the development of the vacuum metallurgical industry in the 1950s, it has been widely used because the vacuum environment has a series of characteristics in the metallurgical process:
First of all, the chemical interaction between the material and residual gas molecules in the vacuum environment is very weak, so it is very suitable for the smelting and refining of ferrous metals, rare metals, ultrapure metals and their alloys, and semiconductor materials.
Secondly, in the vacuum environment, the purpose of molten steel degassing refining and vacuum carbon deaeration can be achieved by reducing the partial pressure of a single gas molecule.
Another feature of the vacuum environment is that at lower temperatures, it has the ability to carry out certain reactions, for example, at the same temperature, some reaction processes are difficult to carry out in the atmosphere, but it is very easy at low temperatures. This is the basic principle of vacuum compound decomposition and smelting of non-ferrous metals.