Microstructures and Mechanical Properties of an Ultra-Fine Acicular Ferrite/Bainite Steel Plate
the ultra-fine acicular ferrite/bainite microstructures were experimentally obtained through proper chemical composition design and advanced thermomechanical processing schedules in pilot reversing mill. At the same time, the formation mechanism of ultra-fine microstructures and its effects on the mechanical properties were analyzed by optical microscopy and TEM technique. The experimental results indicate that: for the tested Mn-Mo-Nb-B ultra-low carbon microalloyed steel, the size of bainitic packets less than 1 μm and the average thickness of pancakes (flatted prior austenitic grains) less than 5 μm were produced when the compression ratio reaches 7 in non-recrystallization region. The excellent properties, that is, tensile strength m R >1000MPa, the percentage enlongation(% EL) A >14% and charpy notch impact KV A >120J (-30 ℃) have been achieved. The high strength accompanying better toughness of the ultra-fine tested steel is correlated with the changes in substructures, i.e. the thickness of pancakes, the width of bainitic packets and denser dislocations pinned by second particles.
S.Q.Yuan G.L.Liang X.J.Zhang
Department of Electromechanical Engineering, Tangshan College, Tangshan 063000, China
国际会议
桂林
英文
1-6
2010-11-16（万方平台首次上网日期，不代表论文的发表时间）