Thin-specification X65 steel-grade pipeline steel of single-stand steckel mill and rolling method

Abstract

The invention discloses thin-specification X65 steel-grade pipeline steel of a single-rack steckel mill and a rolling method. The steel is composed of the following components in percentage by weight:0.03 to 0.07 percent of C; 0.10 to 0.30 percent of Si, 1.30 to 1.70 percent of Mn, less than or equal to 0.015 percent of P, less than or equal to 0.0050 percent of S, 0.040 to 0.060 percent of Nb, less than or equal to 0.10 percent of V, 0.006 to 0.020 percent of Ti, 0.10 to 0.25 percent of Cr, less than or equal to 0.30 percent of Ni, less than or equal to 0.10 percent of Mo, less than or equalto 0.10 percent of Cu, 0.015 to 0.050 percent of Al and the balance of Fe and impurities. According to the rolling method, a blank with the thickness of 150 mm is used for producing the thin-specification pipeline steel plate with the finished product specification of (6-8) mm X65 grade. By controlling the tapping temperature, the coiling furnace temperature, the second-stage initial rolling temperature, the rough rolling final pass reduction rate, the final rolling speed, ACC cooling and the like, the thin-specification X65 steel-grade pipeline steel plate with the performance and the plateshape meeting the requirements is obtained, the productivity and the yield of a rolling mill are improved, and the performance percent of pass is high.

Description

technical field [0001] The invention belongs to the field of steel rolling, and relates to a rolling process, in particular to a rolling process of thin-gauge X65 grade pipeline steel in a single-stand furnace coil rolling mill. Background technique [0002] When a 150mm thick billet is used to roll (6-8)mmmmX65 wide and thin specification pipeline steel plates in a 3500mm steckel mill, the length of the billet does not exceed 4.3m, resulting in low product yield and low production efficiency. If the rolled piece is too long, especially when the length of the rolled piece is greater than 150m, even if the heating temperature and rolling speed are increased, the thickness of the rolled piece will gradually decrease during the rolling process, and the temperature drop of the steel plate will become faster and faster as the length of the rolled piece increases. , especially the temperature drop at the head and tail of the rolled piece is faster. The difference in process tempe...

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Problems solved by technology

[0003] In order to overcome the existing problems in the existing technology about the thin-gauge long-rolled pipeline steel plate, the temperature drop of the rolled piece is too fast, the temperature difference is too large, the performance is inconsistent, and the plate shape is not good. A method for rolling thin gauge X65 grade pipeline steel in a single-stand furnace coil mill

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