The precipitation kinetics in a low carbon high strength low alloy (HSLA) steel,microalloyed with V+Nb has been studied by using the stress relaxation method.This technique was carried out in a dynamic dilatometer and...The precipitation kinetics in a low carbon high strength low alloy (HSLA) steel,microalloyed with V+Nb has been studied by using the stress relaxation method.This technique was carried out in a dynamic dilatometer and allows to determine the onset and finishing precipitation times in hot deformed austenite.The evolution of the precipitates was also observed using field emission scanning electron microscopy (FESEM) on samples quenched at different times at given temperatures.Discussion is completed with the predictions by the thermodynamic software FactSage to identify stable precipitate phases under equilibrium conditions.Results confirm the feasibility of the stress relaxation technique as an efficient method for investigating precipitation kinetics.展开更多
The strain induced effect on the precipitation kinetics of a high strength low alloy (HSLA) steel microalloyed with Nb-V was investigated.The stress relaxation method was employed to determine the dependence of the pr...The strain induced effect on the precipitation kinetics of a high strength low alloy (HSLA) steel microalloyed with Nb-V was investigated.The stress relaxation method was employed to determine the dependence of the precipitation-time-temperature curves (PTT) on previous strain.Relaxation tests were performed over a temperature range of 850 to 1150 oC at a constant strain rate of 0.1 s-1 at three deformation levels,namely 5,15 and 25 pct.Field emission scanning electron microscopy (FESEM) was used to study the progress of precipitation on samples obtained by interrupted relaxation test at different times.Results display the acceleration kinetics at increasing strain.Theoretical models are discussed and compared with the present experimental results.展开更多
基金the support of the Foment Ministry through 80032/A04 Projectthe Ministry of the Innovation Technology and Science through Project MAT 2008-06793-C02-01
文摘The precipitation kinetics in a low carbon high strength low alloy (HSLA) steel,microalloyed with V+Nb has been studied by using the stress relaxation method.This technique was carried out in a dynamic dilatometer and allows to determine the onset and finishing precipitation times in hot deformed austenite.The evolution of the precipitates was also observed using field emission scanning electron microscopy (FESEM) on samples quenched at different times at given temperatures.Discussion is completed with the predictions by the thermodynamic software FactSage to identify stable precipitate phases under equilibrium conditions.Results confirm the feasibility of the stress relaxation technique as an efficient method for investigating precipitation kinetics.
基金the support of the Foment Ministry through 80032/A04 Projectthe Ministry of the Innovation Technology and Science of Spain through Project MAT 2008-06793-C02-01
文摘The strain induced effect on the precipitation kinetics of a high strength low alloy (HSLA) steel microalloyed with Nb-V was investigated.The stress relaxation method was employed to determine the dependence of the precipitation-time-temperature curves (PTT) on previous strain.Relaxation tests were performed over a temperature range of 850 to 1150 oC at a constant strain rate of 0.1 s-1 at three deformation levels,namely 5,15 and 25 pct.Field emission scanning electron microscopy (FESEM) was used to study the progress of precipitation on samples obtained by interrupted relaxation test at different times.Results display the acceleration kinetics at increasing strain.Theoretical models are discussed and compared with the present experimental results.
