550MPa-grade high-strength weathering steel with high aluminum component and preparation method thereof

The invention discloses high-aluminum 550 MPa grade high-strength weathering steel and a preparation method thereof. The high-aluminum 550 MPa grade high-strength weathering steel comprises the following components in percentage by mass: 0.03% to 0.12% of C, 0.05% to 0.40% of Si, 0.8% to 1.8% of Mn, 0.03% to 0.07% of P, 0.00001% to 0.0050% of S, 0.5% to 2.5% of Cr, 0.20% to 0.50% of Cu, 0.50% to 0.90% of Al, 0.06% to 0.12% of Ti, 0.00001% to 0.0050% of N and the balance of Fe and other inevitable impurities. By controlling the addition amount of Cr and adding a relatively high amount of Ti element, good mechanical properties and corrosion resistance are obtained. 本申请公开了一种高铝成分550MPa级高强耐候钢及其制备方法，所述高铝成分550MPa级高强耐候钢以质量百分含量计包括：C：0.03％至0.12％，Si：0.05％至0.40％，Mn：0.8％至1.8％，P：0.03％至0.07％，S：0.00001％至0.0050％，Cr：0.5％至2.5％，Cu：0.20％至0.50％，Al：0.50％至0.90％，Ti：0.06％至0.12％，N：0.00001％至0.0050％，余量为Fe和其它不可避免的杂质。通过控制Cr的加入量和添加较高的Ti元素，获得良好的力学性能与耐蚀性能。