ASM Online Member Community

  • 1.  GAS CARBURIZING: nitrogen/methanol flow rate

    Posted 05-26-2021 06:28

    please, I've been trying to understand which is the proper TOTAL FLOW RATE (40% nitrogen/ 60% methanol) for gas carburizing atmosphere. 

    I found this general information: the ratio flow rate / chamber volume = 1.6 per hour. Is it reasonable?

    Thank you in advance for your support.


    Andrea Talamini Minotto
    Villorba Treviso

  • 2.  RE: GAS CARBURIZING: nitrogen/methanol flow rate

    ASM Employee
    Posted 06-29-2021 09:54

    I am going to recommend @Olga Rowan , Caterpillar Inc. Olga is one of the coauthors of the article on Gas Carburizing in ASM Handbook, Volume 4E. The volume co-Editor, @Jon Dossett might also be able to help answer your question. You could reach out in a private message using the member directory.

    Good luck and have a great week.

    Carrie Hawk
    ASM International
    Community Engagement Specialist


  • 3.  RE: GAS CARBURIZING: nitrogen/methanol flow rate

    Pune Chapter Admin
    Posted 07-03-2021 07:08
    The gas flow rate depends on various factors.
    Chamber volume
    For a 0.4 cubic metre retort with very low leakages, we use 1.5/ 2.0 lph of methanol.
    For enrichment we use lpg at 1 lph 
    This gives us a surface carbon of 0.8 %. We diffuse the case for 30 % of the total carburising time using your only methanol.
    I hope this helps.
    Rahul Gupta