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Time between post quench and Temper

  • 1.  Time between post quench and Temper

    Posted 05-28-2021 07:44

    I am interested looking into an article or book which references/states, how much maximum time one can have after post quench and start of temper on low alloy steels such as AISI grades 41L40/4140 & 43L40/4340. Anybody can help.

     

    Regards,

    Bhaskar Chatrath

    Plant Metallurgist

    ME( Mech.), MBA, BS(Met)

    McGard

    McGard/L.D.McCauley LLC

    3875 California Rd.
    Orchard Park,  NY 14127

    Direct:716-539-3044

    Fax:716-662-8980

    Email:bchatrath@mcgard.com

    Description: logo

     

    CONFIDENTIALITY NOTICE: This communication and any attachment may contain confidential and copyrighted materials, proprietary information and trade secrets of the sender which are only for the use of the intended recipient. All copyrights and intellectual property rights in this transmission and its contents are hereby expressly asserted and reserved by the sender. If you have received this transmission in error, or by unauthorized means, any disclosure, copying, distribution or the taking of an action in reliance upon this communication is strictly prohibited and may result in severe criminal and civil penalties under applicable federal and state laws. If you received this communication in error, please contact the sender immediately and delete the original message. Thank you.


  • 2.  RE: Time between post quench and Temper

    Buffalo Chapter Admin
    Posted 05-29-2021 12:19

    Per AMS2759/2 for heat treating steels to a minimum tensile strength of 220 ksi, tempering should start within 2 hours.  If tempering cannot start within FOUR hours, a snap temper has to be given to the parts.

     

    Lee Gearhart

    Principal Engineer, Materials and Process Engineering

    Moog Inc., 500 Jamison Road, East Aurora NY 14052

    716-687-4475 work   lgearhart@moog.com    716-604-5886 cell

     


    Confidentiality Notice: This electronic mail transmission is intended for the use of the individual or entity to which it is addressed and may contain confidential and/or proprietary information belonging to the sender. If you are not the intended recipient, you are hereby notified that any disclosure, use, copying, distribution, or the taking of any action in reliance on the contents of this information is strictly prohibited. If you have received this transmission in error, please notify the sender immediately by e-mail and delete the original message. Thank you for your cooperation.






  • 3.  RE: Time between post quench and Temper

    Posted 06-01-2021 08:07
    Thank you Lee, Sampathkumar and Nihad,
     I was looking for a specific reference to explain to my team because we had to make a time sensitive decision with risk factors. I did read a lot of literature including ASM Handbook Vol 4 and was unable to find specific info. ASTM reference shall be a great help. Thank you so much again.

    ------------------------------
    Bhaskar Chatrath
    Plant metallurgist
    McGard
    Orchard Park NY
    ------------------------------



  • 4.  RE: Time between post quench and Temper

    Buffalo Chapter Admin
    Posted 05-29-2021 12:25

    Per AMS2759/2 for heat treating steels to a minimum tensile strength of 220 ksi, tempering should start within 2 hours.  If tempering cannot start within FOUR hours, a snap temper has to be given to the parts.

     

    Lee Gearhart

    Principal Engineer, Materials and Process Engineering

    Moog Inc., 500 Jamison Road, East Aurora NY 14052

    716-687-4475 work   lgearhart@moog.com    716-604-5886 cell



    ------------------------------
    Lee Gearhart
    Principal Engineer, Materials and Process Engineering
    Moog Inc
    East Aurora NY
    ------------------------------



  • 5.  RE: Time between post quench and Temper

    Chennai Chapter Admin
    Posted 05-30-2021 05:14
    Tempering should start with minimum 2 hours from quenching .
    is it applicable for all grades of steel? like Low carbon steels .medium Carbon steels   ,medium carbon alloy steels.
    for high alloy steels and HSS any time indicated ?

    ------------------------------
    N. Sampathkumar
    CEO
    Ambattur Metal Treaters
    Chennai
    ------------------------------



  • 6.  RE: Time between post quench and Temper

    Posted 06-01-2021 16:04
    Lee,
    just got the AMS 2759/2. Section 3.4.8 specify" parts should be tempered within 2 hours from the end of quenching". However, in sec 3.4.8.1 it is some what conflicting. As per this standard technically one can have 4 hours from the end of quenching. Correct? 
    Bhaskar

    ------------------------------
    Bhaskar Chatrath
    Plant metallurgist
    McGard
    Orchard Park NY
    ------------------------------



  • 7.  RE: Time between post quench and Temper

    Buffalo Chapter Admin
    Posted 06-02-2021 15:51

    Hi Bhaskar,

    Section 3.4.8 says "Parts should be tempered within 2 hours from..."  By using "should" the sentence indicates it is good practice; it allows enough time to wash the oil off, and leeway for scheduling furnaces, but it is not considered mandatory.  Section 3.4.8.1 is mandatory if it applies; no more than 4 hours can be allowed to elapse from the end of quenching, for fear of causing quench cracking.  So in case the parts washer is broken and it takes longer than two hours to wash them, or in case something is awry with the usual tempering furnace, there's a snap tempering path to follow to avoid quench cracking.

     

    So within 2 hours is good: within 4 hours is mandatory, IF you're working to aerospace practice and following the requirements of AMS2759/2.

     

    All the best,

     

    Lee Gearhart

    Principal Engineer, Materials and Process Engineering

    Moog Inc., 500 Jamison Road, East Aurora NY 14052

    716-687-4475 work   lgearhart@moog.com    716-604-5886 cell

     


    Confidentiality Notice: This electronic mail transmission is intended for the use of the individual or entity to which it is addressed and may contain confidential and/or proprietary information belonging to the sender. If you are not the intended recipient, you are hereby notified that any disclosure, use, copying, distribution, or the taking of any action in reliance on the contents of this information is strictly prohibited. If you have received this transmission in error, please notify the sender immediately by e-mail and delete the original message. Thank you for your cooperation.






  • 8.  RE: Time between post quench and Temper

    Posted 06-03-2021 07:38

    Lee,

                    Thanks for the clarification.

     

    Regards,

    Bhaskar Chatrath

    Plant Metallurgist

    ME( Mech.), MBA, BS(Met)

    McGard

    McGard/L.D.McCauley LLC

    3875 California Rd.
    Orchard Park,  NY 14127

    Direct:716-539-3044

    Fax:716-662-8980

    Email:bchatrath@mcgard.com

    Description: logo

     

    CONFIDENTIALITY NOTICE: This communication and any attachment may contain confidential and copyrighted materials, proprietary information and trade secrets of the sender which are only for the use of the intended recipient. All copyrights and intellectual property rights in this transmission and its contents are hereby expressly asserted and reserved by the sender. If you have received this transmission in error, or by unauthorized means, any disclosure, copying, distribution or the taking of an action in reliance upon this communication is strictly prohibited and may result in severe criminal and civil penalties under applicable federal and state laws. If you received this communication in error, please contact the sender immediately and delete the original message. Thank you.





  • 9.  RE: Time between post quench and Temper

    Posted 05-31-2021 10:06
    The time between Quench and temper for medium C-steel should be 2h or snap tempered for one hour at 400°F (before the final tempering temperature) in order to prevent quench cracking. Quench cracking is due to residual stresses built in such steels during the Martensitic transformation. The cracking depends on the steel C-content and the shape of the parts, that's why usually specifications are very conservative and call for a waiting time of 2 hours for medium and high C-steels.
    in ASM Handbook on "Residual stress and deformation of steel", there is a chapter dedicated to "Hardening by reheating and Quenching" and a paragraph "Quench distorsion and cracking" in which you can find what happen in parts when quenched and consequently how cracking may occur. It does not give a specific time between Quenching and tempering. This is usually stated in industrial process specifications such as SAE-AMS2759 (as Lee wrote).
    You can find explanation on quench cracking in steels in another ASM book "Failure analysis of heat treated steel components" https://www.asminternational.org/search/-/journal_content/56/10192/05113G/PUBLICATION

    ------------------------------
    Nihad Ben Salah
    President
    NBS- M&P Consulting
    Canada
    https://www.nbsmpconsult.com/en/home
    ------------------------------