Relações de orientação resultantes da precipitação de austenita em ferrita em aço inoxidável dúplex. / Orientation relationships resulting from austenite formation from ferrite in duplex stainless steel.

AUTOR(ES)

Eduardo Franco de Monlevade

DATA DE PUBLICAÇÃO

2002

RESUMO

Duplex Stainless Steels have a structure composed by ferrite and austenite. The fact that austenite, in these steels, is stable at low temperatures, allows the use of these steels in studies of austenite formation from ferrite, in such way that the results can be applied to low alloy steels, in which austenite transforms to martensite upon rapid cooling, and to other systems containing transformations between body-centred cubic (BCC) and face-centred cubic (FCC) phases. Studies were performed on a DIN W.Nr. 1.4462 (UNS 31803) duplex stainless steel. The samples were solution treated in the ferrite region at 1325°C and water cooled. Samples were then submitted to isothermal treatments at temperatures between 700°C and 1100°C for up to 30.000 seconds. In this way, austenite formation from ferrite was studied on initial and advanced stages of the reaction, concerning morphological and crystallographic aspects. The morphologies observed varied with the grain boundary segment in which the particles were formed. The grain boundary particles may be adequately described by the Dubé classification. Moreover, these particles presented Kurdjumov-Sachs and Nishyiama-Wassermann orientation relationships with at least one of the adjacent grains, with possibilities of occurrence of intermediate relationships between K-S and N-W relationships. In some cases, the particles show orientation relationships with both adjacent grains, with small deviations form the exact relationships reported in literature. Intragranular austenite particles show higher deviations from the exact relationships than grain boundary particles. In some cases, intragranular particles have no apparent orientation relationships with the ferrite matrix.

ASSUNTO(S)

orientation relationships ebsd ebsd duplex stainless steels aços inoxidáveis dúplex relações de orientação

Documentos Relacionados

• Precipitação de fases intermetálicas e austenita secundária na ZAC de soldagens multipasse de aços inoxidáveis duplex.
• Ferrite Quantification Methodologies for Duplex Stainless Steel
• Contribution to study effects of the turning operations in the surface integrity in a super duplex stainless steel.
• Precipitação de fase de laves no aço inoxidável superferrítico 28%Cr-4%Ni-2%Mo-Nb.
• Avaliação da molhabilidade de soluções de tensoativos em aço inoxidável