Novel low-cost S275JR/J0 low alloy steel plate and production method thereof

The invention discloses a novel low-cost S275JR/S275J0 low alloy steel plate. The novel low-cost S275JR/S275J0 low alloy steel plate comprises, by mass, 0.15-0.17% of C, 0.10-0.25% of Si, 0.3-0.6% of Mn, less than or equal to 0.025% of P, less than or equal to 0.020% of S, 0.010-0.040% of Als, 0.01-0.025% of Ti, 0.31-0.39% of Cr and the balance being Fe and relict elements. In order to obtain the product, a production method adopted includes converter smelting, continuous casting, casting blank slow cooling, heating, TMCP (thermo-mechanical control process) and slow cooling. Through the novel composite micro-alloying composition design thought and simple effective process design, the indexes of mechanical properties, ultrasonic flaw detection and the like of the steel plate are guaranteed; cost of steel per ton is saved by more than 40-60 yuan per ton, meanwhile the requirement of export rebates is met, and good popularization significance is realized.