TY - GEN
T1 - Phase transformation and microstructural behavior of new steel grades for hot sheet stamping
AU - Bruschi, Stefania
AU - Ghiotti, Andrea
AU - Valoppi, Beatrice
AU - Puerta-Velasquez, Juan
AU - Drillet, P.
AU - Arribas, M.
AU - Aranguren, I.
AU - Clobes, J.
PY - 2014
Y1 - 2014
N2 - Since the last few years several researches have focused in proposing new approaches to decrease the energy impact of the hot sheet stamping process. Among them, one possibility is to use steel grades characterized by a lower austenitization temperature in order to reduce the heating energy required for the process, but still maintaining the steel quenchability under the investigated process conditions. In the paper, the behaviour of two new steel grades developed by ArcelorMittal and Tecnalia, and devoted to hot stamping is investigated in terms of transformation kinetics and microstructural behaviour. An extensive dilatometric analysis, performed by using a modified axial extensometer, permitted to evaluate the steel kinetics of phase transformation as a function of the applied cooling rate, amount of strain and strain rate. The micro-hardness of water and die quenched samples of the investigated steel grades was measured and their microstructure analyzed by means of optical and scanning electron microscopy to evaluate the characteristics of the formed martensite and the possible phenomenon of autotempering.
AB - Since the last few years several researches have focused in proposing new approaches to decrease the energy impact of the hot sheet stamping process. Among them, one possibility is to use steel grades characterized by a lower austenitization temperature in order to reduce the heating energy required for the process, but still maintaining the steel quenchability under the investigated process conditions. In the paper, the behaviour of two new steel grades developed by ArcelorMittal and Tecnalia, and devoted to hot stamping is investigated in terms of transformation kinetics and microstructural behaviour. An extensive dilatometric analysis, performed by using a modified axial extensometer, permitted to evaluate the steel kinetics of phase transformation as a function of the applied cooling rate, amount of strain and strain rate. The micro-hardness of water and die quenched samples of the investigated steel grades was measured and their microstructure analyzed by means of optical and scanning electron microscopy to evaluate the characteristics of the formed martensite and the possible phenomenon of autotempering.
KW - Autotempering
KW - High strength steel
KW - Hot stamping
KW - Martensite
KW - Phase transformation kinetics
UR - http://www.scopus.com/inward/record.url?scp=84902590813&partnerID=8YFLogxK
U2 - 10.4028/www.scientific.net/KEM.611-612.1054
DO - 10.4028/www.scientific.net/KEM.611-612.1054
M3 - Conference contribution
AN - SCOPUS:84902590813
SN - 9783038351061
T3 - Key Engineering Materials
SP - 1054
EP - 1061
BT - Material Forming ESAFORM 2014
PB - Trans Tech Publications Ltd
T2 - 17th Conference of the European Scientific Association on Material Forming, ESAFORM 2014
Y2 - 7 May 2014 through 9 May 2014
ER -