Continuous Rolling Simulating Of X65and X52Pipeline Steel

Owing to the increasing of the demand for oil and natural gas, the requirementsfor the quality and performance of pipeline steel are increasing, so it is of importantengineering significance to optimize the existing production process and performanceof pipeline steel.Hot deformation behaviors of X65pipeline steel were achieved by using Gleeble3500simulator, studying the influence of deformation temperature and reduction onmicrostructure. The ferrite grain size decreases, the volume fraction of ferritedecreases and the ferrite changes into acicular from equiaxed with the increasingdeformation temperature and the decreasing strain with the deformation temperaturesfrom750to950℃and the reduction from20%to60%.Continuous rolling and coiling of X65pipe line steel has been simulated by usingGleeble-3500. Effects of the final rolling temperatures, the cooling rate and the coilingtemperature after hot-rolling on the microstructures have been studied. The resultsshow that with decreasing the final rolling temperatures, increasing the cooling rateand reducing the coiling temperatures, the grain size will decrease. The perfectmicrostructure with the ferrite grain size of3.02μm can be obtained by900-850-800℃rolling, coolingat10℃/srate and coiling at550℃.Continuous hot-rolling with three passes of X52pipe line steel has beensimulated by using Gleeble-3500. Effects of the final rolling temperatures, the coolingrate after hot-rolling and the coiling temperature on the microstructures have beenstudied. The results show that with increasing the cooling rate, the microstructure willbe finer. The perfect microstructure with the ferrite grain size of3.72μm can beobtained by900-850-800℃rolling, coolingat20℃/srate and coiling at550℃.