Austenitic Nickel-base Alloys Research Articles

On the Microstructure of Heat-Treated Austenitic Nickel-Base Alloy

A series of heat treatments were preformed to study the evolution of microstructure in an austenitic nickel-base Alloy 690 using optical microscope (OM), scanning electron microscope (SEM) and transmission electron microscope (TEM). The results show that the pre-existed chromium carbides of cold-rolled Alloy 690 were dissolved into the austenitic matrix after high temperature mill annealing (MA) at 1353K for 5min. Mill-annealed and thermally treated Alloy 690 had intergranular M23C6-type carbides. The morphology of intergranular M23C6 varied from continuous, semi-continuous to discrete with the temperature of thermal-treatment (TT) increasing from 873K to 1073K. The holding time at temperature of 988K had less influence on the intergranular carbide appearance than that of temperature. The minimum chromium concentration in the vicinity of intergranular carbides was 22.3 wt% in the sample thermally treated at 715°C for 2h. With the holding time of TT increasing from 2h to 27h, Cr concentration increased gradually and the chromium depletion became wider.

SANDVIK SANICRO 67 COMPOSITE TUBE

Abstract Sandvik Sanicro 67 is a composite tube for various boiler applications. The outer tube layer is of Sanicro 67, an austenitic nickel-base alloy with excellent corrosion and stress-corrosion cracking resistance. This datasheet provides information on composition and physical properties. It also includes information on forming and joining. Filing Code: Ni-673. Producer or source: Sandvik Steel Company and Sandvik AB.

AL 625HP

Abstract Allegheny Ludlum’s AL 625HP is an austenitic nickel-base alloy possessing exceptional fatigue resistance and developed for applications in bellow expansion joints. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming and joining. Filing Code: Ni-594. Producer or source: Allegheny Ludlum Corporation.

SANDVIK SANICRO 41

Abstract Sandvik Sanicro 41 is an austenitic nickel-base alloy with excellent resistance to reducing acids, has better pitting resistance than Type 316SS, and has excellent resistance to stress-corrosion in chlorides and downhole environments. This datasheet provides information on composition, physical properties, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, and joining. Filing Code: Ni-505. Producer or source: Sandvik.

ALTEMP HX

Abstract ALTEMP HX is an austenitic nickel-base alloy designed for outstanding oxidation and strength at high temperatures. The alloy is solid-solution strengthened. Applications include uses in the aerospace, heat treatment and petrochemical markets. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as fracture toughness and creep. It also includes information on low and high temperature performance, and corrosion resistance as well as forming, heat treating, and joining. Filing Code: Ni-442. Producer or source: Allegheny Ludlum Corporation.

A New Age-Hardenable Corrosion Resistant Alloy for Deep Sour Gas Well Service

Alloy 725 (UNS N07725) is a highly corrosion resistant alloy capable of being age-hardened to 0.2% yield strengths from 115 to 140 ksi (793 to 965 MPa), while maintaining a high level of ductility and toughness1 . As alloy 725 is an austenitic nickel base alloy which is strengthened by precipitation of a gamma double-prime (y”) during aging, large section sizes can achieve uniform hardening throughout the cross section. The alloy is resistant to pitting and stress corrosion cracking (SCC) in Deep Sour Gas Well environments containing NaCl, H2S and S at temperatures up to about 450” to 500°F (232” to 26O”C), and to sulfide stress cracking (SSC) in the NACE TM-0177 environment. Alloy 725 also exhibits excellent corrosion resistance to other commercially significant environments, such as seawater and mineral acids.

Grain-Boundary Chemistry and Intergranular Fracture in Austenitic Nickel-Base Alloys—A Review

Abstract Austenitic nickel-base alloys such as alloys 600 (UNS N06600), 690 (UNS N06690), and X-750 (UNS N07750) have been found to be highly susceptible to environmentally-induced intergranular cr...

A Stress Corrosion Cracking Evaluation of Inconel 690 for Steam Generator Tubing Applications

Inconel 690 is an austenitic nickel base alloy that has been considered for use as steam generator tubing in pressurized water reactors. It has a composition comparable to the currently used Incone...

FIRTH FS-718

Abstract FIRTH FS-718 is an austenitic nickel-base alloy having good cryogenic properties, and excellent strength and oxidation resistance up to 1300 F. It is highly recommended for missile and gas turbine components. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as creep. It also includes information on low and high temperature performance, and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Ni-112. Producer or source: Firth Sterling Inc..

JESSOP G.39

Abstract JESSOP G.39 is an austenitic nickel-base alloy having low coefficient of expansion and good thermal shock resistance. This datasheet provides information on composition, physical properties, hardness, and tensile properties as well as creep. It also includes information on high temperature performance and corrosion resistance as well as heat treating and machining. Filing Code: Ni-35. Producer or source: Wm. Jessop & Sons Ltd.