Microstructure And Properties Of X100Pipeline Steel Under Different Final Cooling Temperature

Production of X100pipeline steel under the TMCP process, by changing the finalcooling temperature, X100as the research object, analyzes the structure and mechanicalproperties. Through the appropriate to reduce the final cooling temperature, using the largedeformation, analyzing its microstructure and fine structure and mechanical properties.And precipitates the size of the size and morphology of steel, the results show that as thefinal cooling temperature reduced, to the organization by the polygon ferrite granularbainite transformation, the organization is the optimal organization of X100pipeline steelwant to. We reasonable ingredients from concept design to set up a systematic study.The same composition, different TMCP process, research on six different finalcooling temperature on the microstructure and mechanical properties of its, the influence ofthe paper’s main research results are as follows:（1）the continuous cooling transformation study found that the cooling speed ofcooling speed is1℃/s during continuous cooling, cooling curve from the upper left ofthe right direction of movement, if with ferrite transformation start line intersection, whichoccurred from austenite to ferrite transformation. When the cooling curve and pearlitetransformation start line intersect, and ends with pearlite transformation at the end of theline, formation of proeutectoid ferrite and pearlite.（2）mechanics results show that: to observe the tensile curve of X100pipeline steel,the overall change of X100pipeline steel curve with the loss of the final coolingtemperature and showed a trend of increase, especially the400℃to650℃increasesobviously. Final cooling temperature on the impact properties of the steel-20℃impactresults can be seen that as the final cooling temperature of the lower-20℃in general isthat of the experiment steel rise before they are reduced. In low temperature area, as thefinal cooling temperature rise and rise, peak appears at400℃impact energy, however, when the final cooling temperature continues to rise to500℃, with the increase of finalcooling temperature, does not change significantly impact energy.（3）tissue observed: with the loss of the final cooling temperature experiment ofsteel at room temperature organizational change will be effected according to the quasimultilateral type ferritic to multilateral type ferrite, granular bainite and plate strip bainiteand martensite transformation, organizational change rule of the under the condition ofeach of the final cooling temperature experiment of steel microstructure phasemicrostructure by2-3different phase composition.