Effect of Cooling Methods on Microstructure and Properties of X80 Pipeline Steel

The ordinary X80 pipeline steel was treated using the accelerating cooling method of oil cooling,water cooling and air-cooled three ways,and the microstructure and properties of the test steel after processing were studied by material microscopic analysis method and mechanical properties test.The results indicate that the microstructure and properties of the test steel has certain change rules with the change of cooling rate.Using the oil cooling processing,the ordinary X80 pipeline steel can obtain the(B+F) dual-phases microstructure,which can not only retain original high strength and toughness,but also obtain lower strength-toughness ratio,larger uniform elongation,and higher deformation strengthening index,then the excellent deformation capacity can be acquired.