低合金高强韧稀土铸钢的研究

Study on Low Alloy Rare-Earth Cast Steel with High Strength and Toughness

我国一般工程结构碳钢和低合金钢(含稀土钢)由于成分设计及冶金工艺的局限,其屈服强度均未超过637MPa,且综合性能较差。为了满足产品的特殊需要,提高综合性能,研制了低合金高强韧稀土铸钢。从成分优化设计、炉外喂稀土硅钙线、钢包底吹氩等精炼方面进行工艺控制,有效提高钢的纯净度,冶金效果良好,力学性能达到了115-95、135-125牌号高强韧的要求,其铸造性、可焊性、低温韧性等综合性能良好,适应性强,有广泛的应用前景。

Due to the limit of composition design and metallurgy technology, the yield strength of the national current engineering structure carbon steel and low alloy steel （including rare-earth steel） fail to exceed 637 MPa with poor comprehensive properties. To meet the special requirement of the product, the low alloy rare-earth cast steel with high strength and toughness was developed. Under the following process control measures： optimum design of elements, the rare-earth Si-Ca line to feed outside of furnace and refining technology of ladle bottom blowing Ar, the purity of the steel was effectively improved, well metallurgy effect was obtained, and the mechanical properties were up to the requirements of high strength and toughness of 115-95 and 135-125 grades. The cast steel with good comprehensive properties such as casting, welding, low-temperature toughness, and good adaptability, has wide application prospect.