Method for preparing megawatt wind power high-strength high-toughness and low-temperature spheroidal iron casting

Abstract

The invention relates to a method for preparing a megawatt wind power high-strength high-toughness and low-temperature spheroidal iron casting. The method comprises the following steps of: smelting cast iron serving as a raw material, wherein the smelting temperature is between 1,400 and 1,450 DEG C; spheroidizing, inoculating and recarburizing the raw material, wherein the spheroidizing temperature and the inoculating temperature are between 1,350 and 1,400 DEG C; and casting the obtained product to obtain the low-temperature Ni-free spheroidal iron casting. The formula of the spheroidal iron casting comprises the following components: 3.6 to 3.9 wt percent of C, 1.7 to 2.3 wt percent of Si, 0.1 to 0.3 wt percent of Mn, 0.01 to 0.06 wt percent of Sn, and 0.03 to 0.07 wt percent of residual Mg content. The components of high-strength high-toughness and low-temperature spheroidal iron are obtained by adding a spheroidizing agent and an inoculating agent and using a post inoculation method, wherein the spheroidizing agent comprises the following components: 5 to 8 wt percent of Mg, 1 to 2 wt percent of Re, 40 to 50 wt percent of Si, and balance of Fe. The method can make domestically-manufactured cast iron reach high strength and high toughness as cast condition by optimizing spheroidizing and inoculating methods and recarburization treatment under the condition of adding Sn.

Description

technical field [0001] The invention relates to a preparation method of low-temperature ductile iron, in particular to a preparation method of high-strength and high-toughness low-temperature ductile iron for megawatt wind power components. technical background [0002] Wind energy, as a renewable new source and green energy, is widely and maturely used in Europe, especially megawatt-scale wind turbines, which have become mainstream products in the wind power industry. The country has vigorously developed wind power since 2004, and the country is vigorously supporting wind power projects. [0003] Megawatt-level wind turbines work under harsh conditions, and their main components, such as hubs and bases, are made of low-temperature ductile iron. Ductile iron castings require low-temperature impact toughness. In harsher working conditions (such as offshore wind power), high strength and -40°C low-temperature impact toughness are required. Foreign countries generally adopt th...

AI Technical Summary

Problems solved by technology

For example, Denmark and India add Ni0.5-2wt% when producing high-power wind turbine castings. Nickel is a scarce resource and is expensive.