Results 1 to 3 of 3

Thread: types of tempering

  1. #1
    Join Date
    Sep 2003
    Location
    Mass
    Posts
    1,070

    types of tempering

    while working in 1095 I noticed that there were several variations in tempering. Heating the blade up in an oven seemed to soften it, but that then when using a rosebud colors came into play, tempering to specific colors certain forces some of the brittleness to gaveway to allow more flexibility (aka the blade didn't break when bent) I was wondering a. what colors corrospond to what properties, and b. can this be done in a propane forge, (which is all that I plan to have once I get my set up finished) Is it all about the carbon, or is it about aleviating stresses and then about moving carbon. Thanks

    Bryce
    Last edited by bryce c; 08-10-2004 at 05:15 AM.

  2. #2
    Join Date
    Jan 2003
    Location
    NY State
    Posts
    3,366
    Tempering is tempering regardless of the heat source. First the technical side. When you quench you form martensite which has a tetragonal crystal[elongated cube].Quenching also produced great stresses in the steel. Those stresses can be high enough to fracture the steel so the tempering has to be done immediately.As you temper at higher and higher temperatures carbon comes out of the martensite in the form of iron carbides [cementite] and the the crystal shrinks[ the long axis] in size.The higher the tempering temperature the lower the hardness and higher the toughness....Tempering to color presents a few problems.The color is the color of the oxide of the surface. Metallurgical transformations are temperature and time dependant. We suggest tempering for at least 1 hour to produce a proper stabile structure. That's a lot easier with a tempering oven.With a torch an attempt should be made to hold the steel at the desired temperature for some time....Colors range from faint yellow[425F] , yellowish brown[500F],deep purple[550F], dark blue[600F]. These colors may be slightly different with different alloys.

  3. #3
    Join Date
    Sep 2003
    Location
    Mass
    Posts
    1,070
    so when you want to achieve a "spring temper" which i know is a misleading term what are the traits that I'm looking for, for example, lets assume that I want to make a armor pericing blade. so the tip is not too sharp with a beefy edge geometry at the tip. If I through harden the blade, and then temper to remove the stresses, how should I go abou tempering the remaining metal (and I'm aware that its not sourse dependant, but I wasn't sure if a forge would allow for the correct amount of control, or if the temperature increase had to be gradual, something that a forge might have greater problems with, i had only seen people temper for cementite with a rose bud, I assume for control perhaps to iolate the tempering to certain areas)

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •