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41B30 steel for cast part

  • 1.  41B30 steel for cast part

    Posted 27 days ago
    Hello ASM community,

    I am in need of advice on casting parts from 41B30 steel. I have not found relevant results when searching for cast 41B30, and what I have read about boron's reactivity with oxygen and nitrogen during steel making leads me to conclude that boron steels are not commonly used to produce cast parts and that it may not be a practical possibility. Is there a cost-effective process to cast parts with boron treated steels such as 41B30?

    Thank you,

    Joseph Brown

    Joseph Brown
    Hubbell Power Systems
    Centralia MO

  • 2.  RE: 41B30 steel for cast part

    Pune Chapter Admin
    Posted 27 days ago
    Yes it's possible to cast Boron steels.
    All casting practices would be same as that for an equivalent steel without Boron.
    You need to deoxidise the steel very well.
    First with Ferro silicon.
    Followed by Al around 0.1%
    Followed by Ti around 0.1 %
    After this add the required Boron as a Ferro alloy either in the ladle or furnace.
    Ensure that the sprue is full during pouring .
    Use a non pressurised gating system

    Rahul Gupta
    Managing Director
    N D Gupta Enterprises

  • 3.  RE: 41B30 steel for cast part

    HTS Board Member
    Posted 26 days ago
    I agree you will need to add titanium to react with the nitrogen to form stable TiN precipitates. This is necessary to avoid reacting the boron with the nitrogen, thus making it ineffective for increasing the hardenability. A  ratio of Ti to N of about 4 is adequate. Then add the boron as  FeB as late in the process as possible but still get good mixing

    Robert Cryderman
    Research Associate Professor
    Colorado School Of Mines
    [Golden] [Colorado]
    (734) 735-3093

  • 4.  RE: 41B30 steel for cast part

    Posted 26 days ago
    Hi Joseph,
    I don't know your exact situation so I'm just going to toss out some comments that may be helpful.

    In many alloy systems the cast materials do not exactly match the wrought ones.  The cleanliness of the microstructure, the castability of the particular grade, and so on are some of the reasons.  I did find an ASTM specification,


    Steel Castings, Carbon and Alloy, Chemical Requirements Similar to Standard Wrought Grades

    And an old version at least of this spec does show a 4130, but not a 41B30.

    The reason for the SAE/AISI/UNS specs for steels is strictly for chemistry, which in common manufacturing practice will give the customer a certain range of heat treatment response.  If you're planning to make a part, you have to figure out which properties you want and then tailor your alloy and heat treatment to generate those properties.  It's uncommon for a cast part to have exactly the same shape and thicknesses as a part that has been produced by forging or by machining and welding, just because of the characteristics of these processes.  When a part's shape and thickness is changed, the heat treat response is changed, and a grade that produced the desired characteristics in one process may not have those same properties when produced differently.

    So calling out a composition, but not guaranteeing an identical production process, may not get you the same part.  Even a cast 41B30, if you can find it, will probably have a different grain size and therefore different heat treat response even when treated identically to a forged or a machined from stock part.  If you're looking for a tight range of properties in fact, the H-type steels (4130H) have tighter ranges of min-max hardnesses at a given thickness.  Though again the grain size is a factor that will be different in a casting, and I don't know if the H grades are produced as castings.

    So I am saying that you should produce a casting of a known grade, in the size and shape meeting your requirements, then check its properties (hardness, required toughness, or whatever) and adjust the alloy grade and heat treatment until you get the properties you need, rather than calling out a grade in advance.  Your casting supplier may have the expertise to take a range of thicknesses, and a proposed heat treat schedule, and advise you as to which grades will provide good results.

    And make sure your casting spec calls out when and where welding is allowed for repair and how it is handled and inspected.

    Paul Tibbals