Pipeline steel X70 steel plate in low compression ratio, and production method thereof

The invention provides a pipeline steel X70 steel plate in low compression ratio, and a production method thereof. The pipeline steel X70 steel plate in low compression ratio is prepared from the following components in weight percent: C is 0.030-0.080%, Mn is 1.55-1.75%, Si is 0.10-0.40%, S is not more than 0.0050%, P is not more than 0.015%, Nb is 0.035-0.060%, Ti is 0.008-0.025%, V is not morethan 0.10%, Alt is 0.020-0.060%, Cr is not more than 0.30%, Mo is not more than 0.20%, and the balance of Fe and unavoidable impurities. In the production method of the steel plate provided by the invention, the X70 pipeline steel with low compression rate and thick specification is produced in batch by adopting laminar subsection cooling process, and the engineering technical requirement is satisfied. 本发明提供了种低压缩比管线钢X70钢板及其生产方法。其中，低压缩比管线钢X70钢板按重量百分比包括以下组成成分：C：0.030~0.080%，Mn：1.55~1.75%，Si：0.10~0.40%%，S≤0.0050%，P：≤0.015%，Nb：0.035~0.060%，Ti：0.008~0.025%，V≤0.10%，Alt：0.020~0.060%，Cr：≤0.30%，Mo：≤0.20%，其余为Fe和不可避免杂质。所述钢板的生产方法