非金属夹杂物对重轨性能的影响

EFFECTS OF NON-METALLIC INCLUSIONS ONQUALITY OF HEAVY RAILS

鞍钢生产50 km/m重轨,通常用铝终脱氧,钢中生成链状Al_2O_3夹杂,轨头容易产生剥离等缺陷。为提高其使用寿命,采用硅钙钒镁等复合金属终脱氧,使得夹杂物的组成、形态、分布发生明显变化,导致钢轨疲劳寿命提高30％以上。由于硫含量降低、长条状MnS减少,断裂韧性相应提高3 MPa·m^(1/2)以上。本文对此进行了分析和探讨。

In Anshan Iron and Steel Co., the heavy rail (50kg/m) steel produced with Al as final deo-xidizer usually contains chaintype Al_2O_3 inclusions which easily induce some defects such as pe-elings at the rail head. In order to improve the service life, a final Si-Ca-V-Mg compound deo-xidizer was used. And the composition, form and distribution of the inclusions show distinc0changes for the better, which resulted in raising fatigue life by 30%. Because of low S contentand less chain-type MnS, the rapture toughness was improved by more than 3MPa·m^(1/2) correspo-ndingly.