首页|A novel tri-phase lightweight press-hardening steel exhibiting both excellent mechanical properties and outstanding oxidization resistance

A novel tri-phase lightweight press-hardening steel exhibiting both excellent mechanical properties and outstanding oxidization resistance

扫码查看
A novel Si-Al alloyed press hardening steel(PHS)with the ferrite(α)-austenite(y)-martensite(α')triplex microstructure was developed to have marginal oxidization after the hot forming in air,and the resultant ultimate tensile strength(UTS)of 1620 MPa and total elongation(TE)of 14%were achieved simultane-ously at reduced density.Both performances are superior to the existing PHSs.Particularly,the baking at 170 ℃ leads to remarkable increases in both strength and ductility together with the transition of tensile fracture from the brittle interfacial cracking to the ductile one.This is because austenite and ferrite were hardened due to the segregation of C atoms into geometry necessary dislocations(GNDs)but marten-site softened due to the loss of supersaturated C atoms during the baking.Atomic probe tomography examination reveals that some C atoms segregated to the α/α'interfaces during the baking for increased cohesive energy of the phase interface,thus hindering the interfacial cracking.In addition,the employed Al/Si alloying affords stronger oxidization resistance than both Al/Cr and Si/Cr because they are more rapidly oxidized than Cr to form the dense Al2O3/SiO2 layers for earlier protection.

Press hardeningRetained austeniteMechanical propertiesOxidation resistanceTriplex phaseCarbon segregation

Cancan Ding、Haifeng Zhao、Bin Hu、Dechao Xu、Ru Ge、Chengyuan Deng、Zedong Xie、Hua Chen、Haiwen Luo

展开 >

Department of Ferrous Metallurgy,University of Science and Technology Beijing,Beijing 100083,China

State Key Laboratory of Advanced Metallurgy,University of Science and Technology Beijing,Beijing 100083,China

Shougang Research Institute of Technology,Beijing 100043,China

National Natural Science Foundation of ChinaNational Natural Science Foundation of China

5223301851831002

2024

材料科学技术(英文版)
中国金属学会 中国材料研究学会 中国科学院金属研究所

材料科学技术(英文版)

CSTPCD
影响因子:0.657
ISSN:1005-0302
年,卷(期):2024.196(29)