CCT curves and effect of nickel content on ductility and tensile strength of weathering steel 09CuPCrNi (% ： 0. 08C

0. 34 ~0. 35Cu

0. 091 〜0. 099 P

0. 53 〜0. 55 Cr

0.02 ~0. 27Ni) at 700 〜1 300 ℃ have been measured and studied by using Gleeble 3000 thermal simulator. Results show that with decreasing Ni content to 0. 02% from 0. 27%

the Ar

1

and Ar

3

of steel increase respectively to 710. 1 °C and 882. 5 °C from 670. 2 °C and 860. 0 °C

and the bainite and martensite transformation occur earlier while the high temperature embrittlement zone at 800 °C is widen and that at 950 °C disappears. The tensile strength of 0. 02% Ni weathering steel 09CuPCrNi at ambient temperature is 475 ~485 MPa with elongation 32% ~34% and impact energy 72 ~ 84 J to meet the application requirement of the weathering steel.