1results about How to "High extension" patented technology

The application discloses a 1300MPa or above grade cold-rolled steel plate with high elongation and high hole expanding performance, which contains Fe and inevitable impurity elements, and also contains the following chemical elements with mass percentage as follows: C: 0.15%-0.30%, Si: 0.3%-0.5%, Mn: 1.8%-2.5%, Al: 0.01%-0.03%, B: 0.001-0.003%, Ti: 0-0.05%, and the mass percentage of C and Mn satisfies C+Mn / 6>=0.52; wherein the microstructure of the cold-rolled steel plate has nano precipitates with an average diameter less than 30nm. In addition, the application also discloses a manufacturing method of the above-mentioned 1300MPa or above grade cold-rolled steel plate, which comprises the following steps: (1) smelting and casting; (2) hot rolling; (3) hot coil heat preservation cover annealing; (4) cold rolling; (5) annealing; (6) isothermal heat preservation treatment; (7) cooling; (8) flattening.