Abstract:The final microstructure and subsequent properties of pipeline steel have been shown to be highly dependent of both controlled rolling and accelerated cooling conditions. This research utilized a novel physical deformation simulator to evaluate the final microstructure in an X70 grade pipeline steel after finishing hot deformation and cooling. A series of plane strain compression (PSC) tests have been designed to simulate the processes of plate rolling and strip rolling, with the influence of finishing temperature and cooling rate being of particular interest. Single and multipass reductions at constant strain rates of 70s-1, together with constant delay times were used in this work. A total of three different deformation temperatures, namely, 950 ℃, 900 ℃ and 850 ℃ were used for the present experiments, in which multipass isothermal or nonisothermal deformation(i.e., descending temperature processing) took place, then subject to two different cooling rates, 3 ℃/min and 6 ℃/s respectively. The optical observations showed that the descending temperature processing in this study resulted in a mix grain size, and isothermal 850 ℃ with three hit deformation after 6 ℃/s accelerated cooling achieved uniform and fine ferrite grain with size down to 4.3 μm.
杨雄飞1 ,E.J. Palmiere2 ,付俊岩1. 加工条件对管线钢组织影响的实验研究[J]. 中国冶金, 2007, 17(5): 37-37.
YANG Xiongfei1,E.J.Palmiere2,FU Junyan1. Research on Effect of Processing Conditions on Final Microstructure of a X70 Pipeline Steel. China Metallurgy, 2007, 17(5): 37-37.