Solution heat-treatment of Nb-modified MAR-M247 superalloy

Journal Article · Tue Jan 15 04:00:00 EST 2013 · Materials Characterization

DOI:https://doi.org/10.1016/J.MATCHAR.2012.11.006· OSTI ID:22163178

Baldan, Renato ^[1]; others, and

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1. Universidade de Sao Paulo (USP), Escola de Engenharia de Lorena (EEL), Departamento de Engenharia de Materiais DEMAR, Polo Urbo-Industrial Gleba AI-6, Caixa Postal 116, 12600-970, Lorena, Sao Paulo (Brazil)

MAR-M247 superalloy has excellent mechanical properties and good oxidation resistance at elevated temperatures. Niobium is an element known as {gamma} Prime phase hardener in nickel-based superalloys, besides promoting homogeneous distribution of MC carbides. This work is inserted in a project that aims to evaluate the total replacement of tantalum by niobium atoms in MAR-M247 superalloy (10.2 Co, 10.2 W, 8.5Cr, 5.6 Al, 1.6 Nb, 1.4 Hf, 1.1 Ti, 0.7 Mo, 0.15 C, 0.06 Zr, 0.015 B, Ni balance-wt.%). Based on microstructural characterizations (SEM and FEG-SEM, both with EDS) of the as-cast material and heat-treated materials as well as utilizing Thermocalc simulations and experiments of differential thermal analysis (DTA), heat-treatment at 1260 Degree-Sign C for 8 h was chosen as an ideal condition for the solution of Nb-modified MAR-M247 superalloy. The hardness of as-cast and ideally solution treated materials was 390 {+-} 14 HV and 415 {+-} 6 HV, respectively. - Highlights: Black-Right-Pointing-Pointer DTA and microstructure of MAR-M247(Nb) showed a good agreement with Thermocalc. Black-Right-Pointing-Pointer An ideal condition for solution heat-treatment of MAR-M247(Nb) is 1260 Degree-Sign C for 8 h. Black-Right-Pointing-Pointer It was an observed evidence of incipient melting in samples heat-treated at 1280 Degree-Sign C.

• OSTI ID: 22163178
• Journal Information: Materials Characterization, Journal Name: Materials Characterization Journal Issue: Complete Vol. 75; ISSN 1044-5803; ISSN MACHEX
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
DIFFERENTIAL THERMAL ANALYSIS
HARDNESS
HEAT RESISTING ALLOYS
HEAT TREATMENTS
MICROSTRUCTURE
NICKEL
NIOBIUM
OXIDATION
SCANNING ELECTRON MICROSCOPY
SIMULATION
SOLUTION HEAT
SOLUTIONS