Smelting technique for cast of wind energy apparatus

Abstract

The invention discloses a smelting process of castings of wind energy equipment, which is suitable for the smelting production of castings of wind energy equipment with the wall thickness of 60 to 200mm and includes the following steps: a. new pig iron, scrap steel and carburants with special requirements are sent into a melting electric furnace for smelting; b. high temperature liquid iron is subjected to desulfurization treatment by a desulfurization agent; c. the desulfurized liquid iron is returned into a heat insulation electric furnace for component adjustment, and the carburant is added for carrying out pre-treatment of crystal nucleus to graphite in the liquid iron; d. spheroidization treatment is carried out to the liquid iron; e. an inoculant is added into the liquid iron for inoculation; f. the liquid iron is poured to casting sand mold; and g. the castings are naturally cooled to 500 to 550 DEG C for unpacking after finishing pouring. The smelting process of castings of wind energy equipment can increase the spheroidization efficiency of ductile iron castings used by the wind energy equipment, which causes the castings to have good intensity of tension, extensibility and high impact ductility in low temperature environments, thus meeting the requirements on the castings used by the wind energy equipment.

Description

technical field [0001] The invention relates to the technical field of casting, in particular to a melting process for castings of wind energy equipment. Background technique [0002] Castings are the main components of wind energy equipment, including hubs, bases, gear boxes, mechanical stands and other components of device blades. The wall thickness of such castings is generally 60mm to 200mm, and they are ferrite ductile iron castings. The required tensile strength Intensity σ b ≥370N / mm 2 , yield strength σ 0.2 ≥240N / mm 2 , elongation δ (%) ≥ 12, -20 ℃ impact absorption J: 3 times the average value ≥ 10, single value ≥ 7, casting matrix structure ferrite ≥ 90%, the spheroidization level of metallographic structure is 2 ~ Grade 3, the graphite ball size is 5-8, so the chemical composition, microstructure and mechanical properties of the casting must be fully controlled, the content of silicon, phosphorus and alloy elements should be low, and the spheroidization rate s...

AI Technical Summary

Problems solved by technology

Since the castings used in wind energy equipment are all shell-shaped, if thermal aging treatment is performed, some key parts will be slightly deformed and affect the dimensional accuracy. Therefore, aging treatment of castings is not allowed according to product specifications and user requirements. At the same time, wind energy The castings used in the equipment are basically uniform-wall ductile iron castings, which have extremely high requirements for casting smelting and solidification process. If the smelting process is improperly selected, it is particularly easy to cause the chemical composition and internal microstructure of the castings to fail to meet the requirements. The conversion rate is poor, and it is difficult to meet the requirements of wind energy equipment for the mechanical properties of the casting body

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