Welding Hardened Steel Forum
I have a piece of old snowplow edge I want to use to make the new cutting edge for my bucket.
I’d like to weld it on as I feel it will be much stronger than bolting, and I don’t expect to be able to wear it out in my lifetime (the original lasted over 20 years) so replacing is not an issue.
I can’t seem to find a reference to exactly what sort of steel (other than “high carbon”) it is, so I’m unsure of the best welding technique.
I’m thinking I’ll need to preheat, but I’ve never done that so some guidance would be appreciated. I’m guessing you preheat with an acetylene torch. Questions are:
1. How much pre-heat? Can you go by steel color, like say a dull red?
2. I’d like a continuous weld on the top edge (I’ll just stitch the back) so how much should I preheat and weld at a time? 6 inches or less?
3. What about post heat. My reading indicates that some really brittle stuff required post heat to keep the weld from cracking as it cools.
Any information appreciated.
Stan you are absolutely right, I stand corrected! In the future I will refrain from posting inaccurate information!
But, I didn’t realize Fawteen was doing code work, and I felt that heating his 7018 rods in the oven at 300 degrees was better than a sharp stick in the eye.
I’ am well aware of AWS D1.1 code for storing 7018 welding electrodes. I have three Phoenix rod ovens in my shop. But then again I can’t tell you how many projects I’ve been on in the Puget Sound Area where I poured water out of a can of 7018 to use them. Granted it was not code work, but the work is still there. If this makes you nervous, please use caution when going over the West Seattle Bridge, both I-90 bridges. Highway 516 Bridge over the Green River in Kent. Hood Canal Bridge. Pick a dock anywhere between Dillingham AK, and the Port of Long Beach, CA and I probably worked on it too.
Right from an AWS D1.1 book.
Low Hydrogen Electrode Storage Conditions. All electrodes having low hydrogen coverings conforming to AWS A5.1 shall be purchased in hermetically sealed containers or shall be dried for at least two hours between 450°F and 500°F before they are used. Electrodes having low hydrogen coverings conforming to AWS A5.5 shall be purchased in hermetically sealed containers or shall be dried at least one hour at temperatures between 700° F and 800°F before being used.
Copy of an E-mail from Hobart.
The 7018 will be satisfactory until the seal is removed. Once the seal is removed the electrode will begin to absorb moisture. There is a general mis-understanding of the low hydrogen electrodes. If they are being used on what is referred to as a code job the electrodes must be stored in an electrode oven at a temperature of 300 deg. F and no more than 2 hours worth of electrodes removed by the welder at a time. Most of the 7018 electrodes used in the industry today are improperly stored by the end users and would not meet the hydrogen absorption limits for those (code applications).
The electrodes that we package and sell will not exceed the moisture limits for up to 8 hours, beyond that they will still weld and perform the same as any other 70 series electrode but would not meet the low hydrogen weld deposit specifications.
“Granted it was not code work, but the work is still there. If this makes you nervous, please use caution when going over the West Seattle Bridge, both I-90 bridges. Highway 516 Bridge over the Green River in Kent. Hood Canal Bridge. Pick a dock anywhere between Dillingham AK, and the Port of Long Beach, CA and I probably worked on it too.”
Surely some of those jobs must have involved code work. Welding Hardened Steel
Anyway, I didn’t mean to insult you, and I certainly didn’t mean to get into an argument with you about anything concerning welding.
Lots of people on this forum offer advice that is just plain wrong. I’ve never known you to do that. You are correct, of course, that it won’t do any harm to heat 7018 rods to less than the temperature that Lincoln says is necessary to bring them back to low hydrogen status. Certainly that’s better than a sharp stick in the eye. But what’s the point? If 7018 rods out of a container that you have to pour the water out of work just fine for non-code work like Fawteen’s, why do anything with them? Particularly, why do something that suggests bringing them back to low hydrogen status, but doesn’t? If I said to do that, people would think, “Well, that’s his opinion.” When you say to do it, people take it as a fact. Welding Hardened Steel
You know,if you had say about a 2 inch piece of flat metal tacked on to where you wanted to weld with 7018 and you started your weld on that piece every time before you ran your weld.As long as the rods weren’t soaking wet,they will be heated up real good by the time you get to where you are making a weld on the area you want to be good.Its called a starter strip. Now what the problem is that the first part of the weld is probably going to be bad with a wet rod. It will be good and hot by the time you run 2 inches on it.Dryer rods may not need but one inch.
I’m no scientist,but If I was worried about it being strong enough,and I didn’t have a rod oven that got real hot,thats what I would do! Wink! Ha,ha,ha,ha,ha!!!! Welding Hardened Steel
Tempil sticks aren’t expensive. The laser temperature readers can sometimes be found fairly inexpensive as well. The easiest way to heat it and keep it warm while welding is to use a big propane tiger(weed burner)torch. It will heat it to 3 or 400 degress in no time and can also be used for post heat as well. This is what welding shops use for preheating thick vessels. 400 degree’s is still relatively cold so there won’t be any colour change. A rosebud would take 10 times longer to heat the whole edge and use a fair amount of gas. If you don’t have a tiger torch, you should be able rent one. They cost less than $100 new. The bucket itself won’t need too much preheat, just the cutting edge. There will be enough residual heat on the bucket. You may want to use a stronger XX18 rod than 7018 but 7018 should still work. Burning about 6″ at a time should also be good. Cheaper grader blades are just medium carbon steel and the better blades are heat treated. Preheat and post heat with slow cooling should eliminate any breakage problems. Welding Hardened Steel
I cut a wear edge from a grader blade right down the middle with a torch,because it was so wide, and welded it to the bucket on my loader and just ran a bead all the way across it on top and stitch welded it underneath with a MIG welder,turned up as high as it would go about,and its held good.No preheat or anything,but I suspect that torch cut helped to heat it up because I welded it right after I cut it and stayed after it until I got done.Took a couple of hours. I even broke some other welds on it, using it, and the grader blade edge is still there. You can get those Tempil sticks and heat with them,if you want to.That way you will know what the temperature is. But you are probably doing alright.Even with those tempil sticks I doubt you get anywhere close to red hot,probably 600 degrees or more which is way too hot to touch.