The effect of austempering time after the bainitic transformation on the microstructure and property in a low-carbon bainite steel was investigated by metallography and dilatometry. The results showed that by prolongi...The effect of austempering time after the bainitic transformation on the microstructure and property in a low-carbon bainite steel was investigated by metallography and dilatometry. The results showed that by prolonging the austempering time after the bainite transformation, the amount of large-size martensite/austenite islands decreased, but no significant change of the amount and morphology of bainite were observed. In addition, more austenite with a high carbon content was retained by prolonging the holding time at the bainite transformation temperature.Moreover, with a longer holding time, the elongation was improved at the expense of a small decrease in tensile strength. Finally, the Avrami equation B(RF) = 1-exp(-0.0499 × t^0.7616) for bainite reaction at 350℃ was obtained for the tested steel. The work provided a reference for tailoring the properties of low-carbon steels.展开更多
基金the financial supports from the National Natural Science Foundation of China(NSFC)(Nos.51874216 and 51704217)the Major Projects of Technology Innovation of Hubei Province,China(No.2017AAA116)
文摘The effect of austempering time after the bainitic transformation on the microstructure and property in a low-carbon bainite steel was investigated by metallography and dilatometry. The results showed that by prolonging the austempering time after the bainite transformation, the amount of large-size martensite/austenite islands decreased, but no significant change of the amount and morphology of bainite were observed. In addition, more austenite with a high carbon content was retained by prolonging the holding time at the bainite transformation temperature.Moreover, with a longer holding time, the elongation was improved at the expense of a small decrease in tensile strength. Finally, the Avrami equation B(RF) = 1-exp(-0.0499 × t^0.7616) for bainite reaction at 350℃ was obtained for the tested steel. The work provided a reference for tailoring the properties of low-carbon steels.
