Ni-based heat-resistant alloy

Abstract

Disclosed is a Ni-based heat-resistant alloy that contains C <= 0.1%, Si <= 1%, Mn <= 1%, Cr more than 15% and less than 28%, Fe <= 15%, W more than 5% to 20%, Al more than 0.5% to 2%, Ti more than 0.5% to 2%, Nd 0.001% to 0.1%, B 0.0005% to 0.01%, and the remainder comprising Ni and impurities, wherein the impurities P, S, Sn, Pb, Sb, Zn and As are such that P <= 0.03%, S <= 0.01%, Sn <= 0.020%,Pb <= 0.010%, Sb <= 0.005%, Zn <= 0.005%, and As <= 0.005%, and in addition, satisfy the three equations [0.015 <= Nd + 13.4*B <= 0.13], [Sn + Pb <= 0.025] and [Sb + Zn + As <= 0.010]. With the alloy, an even higher level of strength than with conventional Ni-based heat-resistant alloys can be achieved, while the ductility and toughness after long-term use at high temperature are significantly improved, and the zero ductility temperature and hot processing characteristics are even further improved. Thus, the alloy can be favorably used as a pipe material, a thick sheet for heat-resistant and compression-resistant members, a rod material, and cast articles such as in power generating boilers or industrial chemical plants. The alloy could also contain a specified quantity of at least one ofMo, Co, Nb, V, Zr, Hf, Mg, Ca, Y, La, Ce, Ta or Re.

Description

technical field [0001] The invention relates to a Ni-based heat-resistant alloy. Specifically, it relates to a high-strength Ni-based heat-resistant alloy excellent in hot workability and ductility and toughness after long-term use, and the Ni-based heat-resistant alloy can be used as a pipe material, a Thick plates, rods, forgings, etc. of heat-resistant and pressure-resistant parts. Background technique [0002] In recent years, ultra-supercritical pressure boilers in which the temperature and pressure of steam have been increased to improve efficiency are being newly built in the world. Specifically, it is planned to increase the steam temperature, which has been around 600°C until now, to 650°C or higher, and furthermore, 700°C or higher. This is based on the following factors: energy saving and efficient use of resources, and CO 2 Reduction of gas emissions has become one of the unresolved issues of energy issues and has become an important industrial policy. And th...

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Problems solved by technology

[0005] Fe-based alloys such as austenitic stainless steels have insufficient creep rupture strength for the above-mentioned severe requirements

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