Welding case hardened steel

  1. DrGonzoPOW Member

    Messages:
    41
    Wakefield
    Im wanting to make a security gate for my unit and i was looking into case hardening and fancied a go. My question though is....If i cut a load of box section, then case harden it, would i still be able to weld it all together without and trouble ?? Cheers in advance
     
  2. pedrobedro

    pedrobedro Man at Matalan

    Messages:
    10,514
    Location:
    CX Derbyshire
    Case hardening is used to improve the abrasive qualities of the metal surface, pretty pointless on a set of gates unless they get dragged against something a lot.
     
  3. rtbcomp

    rtbcomp Moderator Staff Member

    Messages:
    18,614
    Location:
    Sheffield UK
    Wouldn't it make a bit more difficult to saw through? It is a security gate rather than garden gates.
     
  4. DrGonzoPOW Member

    Messages:
    41
    Wakefield
    Thats the idea!
     
  5. rtbcomp

    rtbcomp Moderator Staff Member

    Messages:
    18,614
    Location:
    Sheffield UK
    An alternative to consider would be to put hardened round rods loose inside the box section, these would be difficult to cut through as they would rotate.
     
    nickk likes this.
  6. DrGonzoPOW Member

    Messages:
    41
    Wakefield
    Thats a good call mate, might get a little expensive though. Just need to know if hardened steel is weldable really
     
  7. R Kraft Member

    Messages:
    978
    Wyoming,USA
    It should weld fine,I have never noticed that hardness effected the metal melting.
    Where the welds are may not be hardened anymore.
    Robert
     
  8. scott0031 Member

    Messages:
    1,054
    England Kent
    My best advice would be just to design the thing properly and make it as hard as you can to be attacked physically. The way you are thinking of making this is ass about face. The normal procedure would be to make the thing, then get it cased. I think i can safely say you probably would not want to pay the price of heat treating these days, plus you have to find someone who can actually do the size you want, pending on where you are in the country that can be tricky now days.

    One thing to remember with casing is, sometimes the actual hardness is a bit unpredictable with mild steel. Often they wont get up any where near the hardness of dedicated heat treatable alloys, this in short can mean they can still be cut by easy means even with a hack saw, if the hacksaw blade is harder than the material being cut it, will cut it, although with difficulty to get through the skin. There are other heat treatment process to case harden but they get more and more expensive as you go down the line.

    Another consideration of casing/ hardening is this: The depth of the case. typical traditional casing can reach a depth up up to 1.5 mm known as max depth( this does not include the DIY kasinit version, which can only produce a very shallow depth) Say you make this door out of 3 mm box that means you will case the thing all the way through, this is actually very detrimental. Things that are hard are also very brittle, which is not what you want, brittle breaks very easily as has no strength at all, this means to get strength out of something that is hardened means it has to be tempered or 'let down' as its know in the trade. So from that point of view you are nullifying the effect you are trying to gain. Even with a thicker steel the core will be so small it wont have the desired effect you are wanting.

    The best thing would be to make the thing so heavy its daunting for any thief and make it so it takes a long time to get through. I would do this by making runners the bar will sit in. Make the perimeter frame slide your bars in but make runners that sit inside the frame. In short, some decent size strip 10 x 40 or something similar slide the bars through the runners( inside the frame) make as many as these as you wish, the more you put in the harder it is to overcome.

    Each time you add a runner you are effectively making a new frame inside the main frame, this means for each runner you put in, it's 2 times the cutting to make a hole to give access. The more runners the more cutting, more cutting more time and noise, they will walk away.

    Remember all security devices are only as good as the thing they are attached to.

    Kind regards


    Scott
     
  9. awemawson Forum Supporter

    Remember case hardening is only a few thou thick, so it will make virtually no difference to the welding, and although it would help against a hacksaw it would make little difference if attacked by angle grinder.
     
  10. I can't imagine anyone cutting through a gate frame.

    I would have thought that either the lock or the hinges would be the easiest to attack.


    As an aside my local pub landlord has an outside bottle store.
    To comply with his insurance it has a steel door, very heavy duty hasp & staple with concealed rounded bolt fixings,
    and a huge Thatcham approved padlock that cost £150. Hardened LAS parts and anti drill.

    Yup, you've guessed. He lost the keys. :ashamed:

    To cut a long story short he phoned me. It was 9.30am and was in a blind panic. "I open at 10 and need to stock up." (In a high pitched voice)

    Armed with my trusty Makita 4.5" grinder with a 1mm slitting disk (inox stainless) I went down.

    He stood back and watched.
    20 seconds later the padlock lay on the ground. :o

    Cheers,
    Paul G
     
    monky harris, Hopefuldave and mike os like this.
  11. 400-ascona

    400-ascona Member

    Messages:
    76
    Derby England
    At the end of the day its about making it difficult, as there will alway's be someone who finds a way around your security. However if the unit next door, or the house next door is an easier target then they probably won't bother with yours.
    I have CCTV camera's up just because all my neighbours don't. I have made it obvious I have them so hopefully (touching wood!) they will steer clear of my stuff.
    Rob
     
  12. Robotstar5

    Robotstar5 Casanunda Staff Member

    Messages:
    18,173
    Location:
    Birmingham
    I'm glad I'm not one of your neighbours :laughing:
     
  13. pedrobedro

    pedrobedro Man at Matalan

    Messages:
    10,514
    Location:
    CX Derbyshire
    They might think you are the only one with anything worth nicking though, have you thought of that :D My brother in law was burgled and they took his CCTV system as well.
     
    Hopefuldave likes this.
  14. bunnymofo Member

    Messages:
    41
    scotland
    that made me LOL :clapping::clapping::clapping::clapping::clapping::clapping::clapping::clapping::clapping:
     
  15. madkayaker

    madkayaker Pro sparkey Pro Welder

    Messages:
    13,694
    Cumbria
    that made me chuckle. scureity is only as good as weakest link i do a fair bit of work on MOD sites and stuff is going missing all the time. the weak link? staff that don't care as its not theres
     
  16. Hitch

    Hitch Moderator Staff Member

    Messages:
    12,315
    Somerset
    When i did a bit on security stuff, biggest problem was internal theft, robbing staff.
     
    northwest likes this.
  17. Pete.

    Pete. Member

    Messages:
    9,490
    Location:
    Kent, UK

    There's nothing worse than getting your staff pinched :D
     
    Hopefuldave likes this.
  18. TechnicAl

    TechnicAl Member

    Messages:
    7,819
    Location:
    Rotherham
    There are a few issues
    You wont really harden mild steel that much
    You will distort the sections heat treating them
    You really should remove the surface before welding

    Its easier to buy some hardfacing rods. Get some Chromium Carbide types (about 30%Cr and 5% Carbon and put a run in the strategic places. You wont hacksaw it and even though grinding is possible it will take ages even with the special soft discs.

    Oh and you cant burn it with Oxy Acet
     
  19. dannyp Member

    therad old wire rope down through the box sections, that'll pritty much stop hacksaws grinder OA and plasma still work tho.
     
    tom2207 and mike os like this.
  20. Mohsenp New Member

    Messages:
    5
    Location:
    Iran
    i want to select an Mig/Mag wire for DIN 1.6566 that it is a kind of case hardening steel.Would you tell me suitable GMAW wire code for welding this material?
     
Advertisements