The production process and actual product performances of ASTM A 387M Gr. 11 CL2 steel 24 mm plate for pressure vessels produced by Chongqing Iron and Steel Co Ltd are introduced. The rolling process and heat treatment of test steel (/% ：0.13C

0.56Si

0.56Mn

0.036Alt

0.005P

0.001S

l.02Cr

0.50Mo)300 mm x2010 mm casting slab are rough rolling at >1000 °C

thicknees of middle bloom 72 mm

finishing rolling at 880 ~ 940 °C

end finish rolling at 850 ~870 °C

laminar cooling to 690 -710 °C

air cooling to room temperature and normalizing at 890 〜910 °C

tempering at 650 ~ 670 °C. Practice shows that the performance indexes of the steel meet the technical requirements and the steel has good impact toughness at low temperature

i. e. the impact energy of test steel at -40°C is 149 ~ 172 J.