Microstructural evolution during the processing of ultrafine grain size steels
Two different methods for producing ultrafine grain sizes are described and compared.The fast,based on conventional dynamic recrystallization,involves warm rolling just below the intercritical temperature range and is particularly well suited to interstitial free steels.Total finishing strains about 2.5 are required,which lead to grain sizes in the 1-2 μm range.This is an order of magnitude finer than achievable by finish rolling in the austenite range.The second method is based on dynamic strain-induced transformation(DSIT)and can be employed on microalloyed steels.This again requires the application of large finishing strains:e.g.3.5-4 for grain sizes of 1-1.5 μm,respectively,and 5 for grain sizes ＜ 1 μn.In this case,the finishing strain must be applied just above the Ar3 and,for this purpose,the large-strain Ar3 must be accurately known.
ultrafine grain steels dynamic recrystallization dynamic strain-induced transformation interstitial-free steels microalloyed steels Ar3 Ar1
John J Jonas
Materials Engineering,McGill University,3610 University St.,Montreal,H3A 2B2,Canada
国际会议
上海
英文
229-234
2008-09-26（万方平台首次上网日期，不代表论文的发表时间）