Nickel creep rupture strength

For resistance against fatigue, Nimonic 75 has been used with Nimonic 80 and Nimonic 90. Nimonic 75 is an 80-20 nickel-chromium alloy stiffened with a small amount of titanium carbide. Nimonic 75 has excellent oxidation and corrosion resistance at elevated temperatures, a reasonable creep strength, and good fatigue resistance. In addition, it is easy to press, draw, and mold. As firing temperatures have increased in the newer gas turbine models, HA-188, a Cr, Ni-based alloy, has recently been employed in the latter section of some combustion liners for improved creep rupture strength. 

Table 11.2. Creep rupture strength of several alloys (after [39,125,129]). The creep rupture strength iim/iooooo/T i- e., the stress needed to cause fracture in a specimen at temperature T after 10 hours (creep rupture time), is stated. The creep resistance of the ferritic steels with large amounts of vanadium and chromium is significantly larger than that of simpler steels because vanadium and chrome carbides have a better temperature stabihty. Due to their close-packed face-centred cubic structure, the creep resistance of austenitic steels is larger. The creep strength of the nickel-base superalloys IN 738 (polycrystaUine) and SC 16 (single crystalline) were estimated from Larson-Miller data...

Creep Rupture. Metals and their alloys lose appreciable strength at elevated temperatures. For most materials, the ultimate tensile and yield strengths fall off regularly as the temperature iacreases, as illustrated ia Figure 2 (2). The exceptions are some iatermetaUics, eg, nickel aluniinide(3 l)... 

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