DING Hua
,
LI Hua-ying
,
DING Hao
,
QIU Chun-lin
,
TANG Zheng-you
钢铁研究学报(英文版)
Two steels without and with Nb addition were chosen to investigate the effects of Nb on the microstructures and the mechanical properties of Fe-Mn-Al-Si steels. The results revealed that Nb refined the grains markedly and both TRIP and TWIP effects occurred during deformation process. The Nb containing steel possesses higher yield strength and much lower tensile strength, the latter being explained by the suppression of TRIP effect due to the increase of stacking fault energy. This indicates grain refining is secondary for strengthening of steels when TRIP or TWIP effect exists during the deformation of low carbon and high Mn steels.
关键词:
grain size
,
strength
,
high Mn steel
,
Nb
TANG Zheng-you
钢铁研究学报(英文版)
Paint baking treatment was carried out in a silicon oil bath at 170℃ for 20 min for Si-Al-Mn TRIP Steel sheet with different pre-strains, effect of pre-strain on microstructures and properties was studied before and after baking. The results is shown that with the increasing of pre-strain amount during pre-straining and baking, the volume fraction of retained austenite decreases, the volume fraction of martensite and bainite increases, as well as yield strength enhances; as pre-strain ranges from 0 to 4%, the bake-hardening(BH) value increases; while from 4 to 16%, the BH value decreases; when the pre-strain amount is 4%, the highest BH value is about 70MPa in Si-Al-Mn TRIP Steel sheet with niobium, which displays excellent bake-hardening behavior.
关键词:
TRIP steel sheet;pre-strain;retained austenite;bake-hardening
