STP665

    Slow Strain-Rate Stress Corrosion Testing of Metals in Gaseous Atmospheres at Elevated Temperatures

    Published: Jan 1979


      Format Pages Price  
    PDF (392K) 19 $25   ADD TO CART
    Complete Source PDF (8.3M) 19 $118   ADD TO CART


    Abstract

    A total of six different alloys—stainless steel (SS) Types 310, 310S, 347, and 446, and nickel alloys 800 and 671—were tested using the slow strain-rate test technique in oxidizing/sulfidizing and in oxidizing/sulfidizing/carburizing simulated coal gasification environments, and in helium (and other inert environments) at both 450 and 600°C at a strain rate of 10-6/s. Of the six alloys, four (Types 310 stainless steel and 310S stainless steel, nickel alloy 800, and nickel alloy 671) were found to be susceptible to cracking at 600°C by possibly different mechanisms, however, all were detected by the slow strain-rate technique.

    For cracking, the nickel alloy 671 required no reactive environment; it suffered internal cracking in helium and all other test environments used. However, the stainless steel Type 310, Type 310S, and nickel alloy 800, all of which failed through surface initiated cracking, required increasingly severe environments for cracking. The Type 310 stainless steel required very little reactive environment; it cracked not only in the simulated coal gasification gases but also in low vapor pressure O2 or water (H2O) environments, or both (for example, helium), as did the Type 310S stainless steel, although with greater ductility than the Type 310 stainless steel. The nickel alloy 800 required the rather reactive environment of the simulated coal gasification gases; it did not crack in the low vapor pressure O2 and H2O environments.

    The detection of the environmentally independent failure of Alloy 671 shows that the use of the slow strain-rate technique need not be limited to use for testing for susceptibility to cracking by stress corrosion cracking. The slow strain-rate technique is shown to be a viable testing method for detecting an alloy's propensity to premature failure in simulated coal gasification environments.

    Keywords:

    austenitic stainless steels, coal gasification, elevated temperatures, ferritic stainless steels, gaseous environments, nickel alloy 671, nickel alloy 800, oxidizing/sulfidizing gas, oxidizing/sulfidizing/carburizing gas, premature failure, slow strain-rate test technique, stress corrosion cracking, Type 310 stainless steel, Type 310S stainless steel, Type 347 stainless steel, Type 446 stainless steel


    Author Information:

    Ugiansky, GM
    Metallurgist and physical science technician, National Measurement Laboratory, National Bureau of Standards, Washington, D.C.

    Johnson, CE
    Metallurgist and physical science technician, National Measurement Laboratory, National Bureau of Standards, Washington, D.C.


    Paper ID: STP38112S

    Committee/Subcommittee: G01.04

    DOI: 10.1520/STP38112S


    CrossRef ASTM International is a member of CrossRef.