本发明公开了一种厚规格高韧性X80管件钢钢板及制造方法。采用低碳“Nb+Mo+V+Ni+Ti”多元微合金独特成分设计，保证厚规格X80管件钢在热处理后具有优异的强度富裕量和高韧性性能，利用高洁净钢和无缺陷连铸坯渐进式柔性轻压下技术，改善钢中夹杂物，使钢中各类夹杂物级别≤1.5级，消除钢坯乃至钢板裂纹缺陷，借助TMCP轧制和全程系统消应力工艺提高厚规格X80管件钢板的韧性性能，改善钢板板形，借助高温回火热处理工艺，实现热扩散处理，释放内应力以及改善钢板中心线区域的组织结构和韧性；解决了X80级别管件钢板热处理后强度富裕量偏低、韧塑性差、焊接性能不良、整板性能均匀性差、板形不良等问题。

The invention belongs to the field of iron and steel materials, in particular to X90 pipeline steel with high strength and toughness containing rare earth elements La and Ce and a rolling method thereof. The chemical composition of the steel is as follows: C: 0.040 ~ 0.055%; Si: 0.20 ~ 0.30%; Mn: 1.6 ~ 1.8%; Cu: 0.20 ~ 0.30%; Ni: 0.30 ~ 0.40%; Mo: 0.20 ~ 0.30%; Cr: 0.30 ~ 0.40%; Nb: 0.07 ~ 0.09%; Ti: 0.01 ~ 0.03%; La+Ce: 0.0040 ~ 0.0060%; P 0.0050% or less; S 0.0010% or less; O 0.0010% or less; We have a margin of Fe. By adding rare earth elements La and Ce into ultra-pure steel (ultra low O and S content), the pipeline steel obtained by controlling smelting, casting, rolling and cooling processes has good tensile properties and low temperature impact properties. The microstructure of hot rolled steel plate is superfine acicular ferrite with effective grain size less than 2μm.