热轧耐候钢板B490NQ的研制

Development on Making B490NQ Hot Rolled Weathering Steel

从耐候性和强韧性机制出发，确立了以ＣＵ、Ｐ为耐蚀元素、以Ｔｉ为微合金元素的低碳低杂质成分范围，及以高纯度冶炼、高质量成坯、高精度控制为特．点的工艺路线。研制的经济型热轧耐候钢板Ｂ４９０ＮＱ耐候性比普通钢提高４０％，抗拉强度达到４９０ＭＰａ，综合性能良好，－４０℃的ａｋ值大于３０Ｊ／ｃｍ２。

To achieve excellent weatherability and strength and toughness,a composition range of low-carbon, low inclusion with copper and phosphorus as the corrosion-resistance elements and titanium as the micro alloy element is established. Accordingly a technological process characterized as high purity steelmaking, quality casting and high; precision control comes into being. The developed economic type hot rolled weathering steel plate (B490NQ) has a simple composition and a combination of good weatherability and strength and toughness. Weatherability of B490NQ plate is increased by 40% as compared with the ordinary steel plate. Its tensile strength is up to 490MPa and the comprehensive properties is good. The value of ak is more than 30J/cm2 at-40℃.