Control method for producing low temperature spheroidal graphite cast iron

Abstract

The invention discloses a control method for producing low temperature spheroidal graphite cast iron, and relates to spherical graphite-containing cast iron alloy. The control method comprises the following steps of: weighing 3.4 to 3.9 mass percent of C, 1.8 to 2.5 mass percent of Si, 0.1 to 0.4 mass percent of Mn, 0.035 to 0.07 mass percent of residual Mg and the balance of Fe, smelting and desulfurizing in a cupola furnace, transferring to a medium-frequency induction furnace for continuous smelting, adding a spheroidizing agent and an inoculators for spheroidization and inoculation, and casting to obtain a spheroidal graphite cast iron casting for a wind turbine. In the method, by controlling the components of the spheroidal graphite cast iron and improving a spheroidization and inoculation process, the number, size, morphology and distribution of graphite nodules are controlled; the cupola furnace and the medium-frequency induction furnace are adopted for double smelting; and the produced spheroidal graphite cast iron casting meets the impact toughness requirement and strength requirement at low temperature of wind turbine castings, and overcomes the defect that deformation or stress concentration easily occurs when the spheroidal graphite cast iron casting is subjected to heat treatment in an annealing mode, and defect of high cost in the prior art.

Description

A control method for the production of low temperature nodular cast iron technical field The technical scheme of the invention relates to a cast iron alloy containing nodular graphite, in particular to a method for controlling the production of low-temperature nodular cast iron. Background technique In recent years, with the rapid growth of people's demand for green energy and renewable energy, wind power has developed by leaps and bounds. Since wind farms are mostly built in places with strong winds such as beaches or grasslands, wind turbines have to withstand salt spray erosion, wind and sand blowing, severe cold and heat, sun and rain, and the operating environment is very harsh. It also requires the unit to have a service life of 20 years, so the requirements for the quality of the castings in the wind turbine are particularly high. The hub is one of the most important large-scale castings in wind turbines. It connects the fan blades with the power shaft. Its shape i...

AI Technical Summary

Problems solved by technology

The technical problem to be solved by the present invention is: to provide a control method for the production of low-temperature ductile iron, by controlling the composition of ductile iron, improving the spheroidization and inoculation process to control the number, size, shape and distribution of graphite nodules, using cupola and intermediate frequency induction A low-temperature as-cast nodular cast iron casting was prepared by double-melting in an electric furnace, which not only meets the impact toughness and strength requirements of wind power castings at a low temperature of -40°C, but also overcomes the shortcomings of high production costs