COBEM99

S3 Ciências dos Materiais

Title:

ANYSOTROPY INDEXES DETERMINATION IN HSLA STEELS

Summary :

MATERIALS WHICH STRUCTURE HAS A PREFERABLY GRAIN ORIENTATION AFTER DEFORMATION PROCESSES ARE CALLED ANISOTROPIC MATERIALS, SINCE THEY COULD PRESENT, FOR EXAMPLE, DIFFERENT BEHAVIOR WHEN DEFORMED (LIKE VARIATION IN THE THICKNESS OF SHEETS IN A SPECIFIC DIRECTION AFTER METAL FORMING). THIS PAPER PRESENTS A STUDY CONCERNING THE ANISOTROPIC BEHAVIOR OF TWO HIGH-STRENGTH LOW-ALLOY STEELS, HAVING FERRITE-MARTENSITE (DUAL-PHASE) AND FERRITE-PERLITE GRAIN-REFINED STRUCTURES. THE ANISOTROPIC BEHAVIOR QUANTIFICATION WAS POSSIBLE THROUGH THE DETERMINATION OF THE MECHANICAL PROPERTIES AND THE NORMAL AND PLANAR ANISOTROPY INDEXES. IT HAS BEEN CONCLUDED THAT THE MORE ACCENTUATED ANISOTROPIC BEHAVIOR OF FERRITE-PERLITE GRAIN-REFINED STEELS IS MICROSTRUCTURE-DEPENDENT, AND THE ELEVATED MECHANICAL RESISTANCE VALUES, ASSOCIATED WITH HIGH DUCTILITY, ARE RELATED TO THE VERY REFINED STRUCTURES FOUND IN THE TWO STEELS, AND THE PRESENCE OF MARTENSITE ISLANDS IN THE DUAL-PHASE STEEL. THIS PAPER CONFIRMS PREVIOUS WORK, CONCLUDING THAT ANISOTROPY INDEXES DETERMINATION IS MORE PRECISE WHEN PERFORMED IN HIGH UNIFORM PLASTIC DEFORMATIONS. CONSIDERING THE COMBINATION OF MECHANICAL RESISTANCE, ELONGATION AND FAVORABLE ANISOTROPY INDEXES, THE DUAL-PHASE STEEL IS THE BEST CANDIDATE FOR SHEET METAL FORMING, UNLESS WELDING IS NECESSARY, WHERE FERRITE-PERLITE GRAIN-REFINED STEELS ARE THE BEST CHOICE. KEY WORDS: ANISOTROPY, HSLA STEELS, MECHANICAL PROPERTIES, FERRITE-PERLITE GRAIN-REFINED STEELS, DUAL-PHASE STEELS.

Author :

BORTOLUSSI, ROBERTO 0
LIMA, CLARISSA GARCIA
MAGNABOSCO, RODRIGO 0
MATHEISEN, ALEXANDRA SILVIA

Paper View :