Welding hardened steel

[Fawteen]

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.

 

[Anonymous-0]

You don't need to preheat or postheat, but you
do need to weld it with 7018 rods.
L A

 

[snoop-nc]

When I had the cutting edge replaced, guy used 7018 rod and did nothing special. A few tacks then continuous bead. My new edge was/is as you described yours....part of a plow edge.

I had enough edge left over to put a piece on each side of bucket that nearly runs full height.

Rick

 

[Fawteen]

Good, thanks. I have plenty of 7018.

 

[PKurilecz]

Without knowing the alloy it is virtually impossible to provide any advice beyond maybe, possibly and likely.

The first problem is to prevent weld cracking as the weld metal cools and the formation of untempered martensite. The formation of martensite comes when the cooling rate is sufficiently fast to prevent the material from transforming from austentite to perlite+ferrite or bainite.

The second problem is to normalize the weld area.

The first problem is relatively easy to solve. The preheat needs to be above the martensite transformation temperature. This can be definitely assured with a preheat in the 300F to 500F range.

The second problem is harder to solve as the weld area would need to be held at ~1,000F to ~1,200F for at least an hour and then cooled slowly.

If you have some spare pieces try practicing first to develop your welding procedure. Multiple passes with a lower heat input will definitely be better. The follow up passes will help normalize the prior weld passes to some degree.

As to type of rod, this is definitely hard to answer with out knowing the alloy type. But suffice to say, the snow plow blade steel probably has a very high carbon equivalent. You may wish to consider using a rod that has some nickel in it. You may wish to treat this similar to cast iron.

hth

pkurilecz

 

[Ken-Pa]

Well golly Fawteeen , where you been ? I haven't seen you on here for quite a spell . I used up an old snowplow cutting edge years ago on my loader bucket also . It worked out well & as said 7018 lays down nicely . Be sure to clamp it good with several clamps to prevent it from walking on you . God bless

 

[Fawteen]

My previous experience working with plow edge reflects your comments exactly. Welded up a subframe for mounting to my loader arms and the first time I pushed on it, it broke.

The welds held, but the material around them fractured and actually ripped chunks out of the base metal. Recent reading and your post seem to point to martensite formation.

I've got a lot of time invested in this bucket and it's coming along very nicely, so I DO NOT want to screw it up at this point.

I'm thinking I'll just go back to the original plan of using mild steel to double the edge and deal with the wear. It's only going to get used in loose dirt and manure anyway.

 

[Fawteen]

I've been all over this board the last couple of days trying to get my new loader bucket built. "8^)

Other than that I normally hang out on Tales and Tractor Talk.

 

[Dick L]

I do a bit of welding hard mold steel but not one piece to another. I would also vote for 7018.

When I have a lot of filler to repair a piece of mold steel I use 7018. When machining it back it will be almost as hard as the base steel right next to the base. It will be softer as you get away from the base steel. I never had any 7018 break away from the base steel.
The tonage I place on the welded steel is straight against and not a side force as you would have but I wouldn't worry about it myself.

 

[PKurilecz]

Even preheating to 150F on ordinary carbon steels can help produce more ductile welds, especially with thicker sections.

Good luck with your project and let us know how it turns out.

Post some pictures if you can.

 

[PKurilecz]

btw, your welding supply shop should have some tempilsticks or other brands of heat crayons to determine temp. I have several and wouldn't think of welding without them.

hth

pkurilecz

 

[Puddles]

Fawteen technically you should preheat everything. It helps control the “HAZ” Heat Affected Zone.
If nothing else preheat to 50-degrees minimum. Post heat can help with the HAZ also. Post heat can be nothing more than covering the object with some home insulation, and letting it cool slowly.

If the cutting edge was AR-400 I'd preheat it as much as 300-degrees. A good rule of thumb for 300-degrees is you can touch it with your bare hand real quick, but not too excited about doing it again in the next few minutes!

You should implement this technique in all of your welding, I do!
It's called back stepping, and skipping around.
On your bucket project if you started welding at one end and worked your way to the other, I guarantee it will warp!

 

[Fawteen]

Thanks.

I've been junkyard welding long enough that I've discovered the dangers of warping the hard way "8^). TIGing stainless sheet will teach you that REAL quick.

All the welding on the bucket has been as you show, tack both ends and the middle then stitch alternately. So far, no warping!

Did have one little blow-through when welding up a gap with 6011. Leetle too hot, hung around a little too long.

I've flip-flopped a dozen times on this cutting edge thing. I REALLY want to weld the hard stuff on and never worry about it again. I have no clue what alloy the stuff is and no way to find out. Guess I need to get off the dime and try some preheat and weld, see what happens.

 

[Puddles]

(quoted from post at 10:19:14 03/08/11) Guess I need to get off the dime and try some preheat and weld, see what happens.

That's what I'd do.
Put your 7018 in the oven, (kitchen oven will work too) at 300-degrees for a few hours. Preheat the base metal to 300-degrees, weld it like I showed, and wrap it up with some old insulation.
You'll be fine! :wink:

 

[Butch(OH)]

In my experiance is pre-heating cant hurt but may or may not be actualy needed. It depends on BOTH steels, the edge and the lip, the rod used, the welders technique, and how cold it is when welding it on. Have yet to see the edge that could be welded on without preheat when its zero out. It"s darned uncomfortable to next to a 300 lip and weld and in your case it isnt free to heat it to 300 degrees. Because we were only concerned with our discomort while welding we used to weld a 4" or so tack on the end, stop and while taking a smoke break listen for the PING of a crack and look over the tack, if it looked good when done with the smoke we (with shorter or lighter edges) would grab it and try to pull it off the lip. You will at that point know if you need to preheat it. This was with 70 and 11018 rod depending on the edge supplier.

 

[jokers]

Even Tractor Supply has temp sticks locally.

 

[jokers]

Puddles,

Do you feel that 7018 is the best rod to use if something else hasn't been recommended by the supplier? The reason I ask is because I was recently(last week) told that 9018 is what is generically used to weld T1 cutting edges on decking blades, but although the guy who told me that has welded a few, he's not a pro weldor.

My welds with 7018 flow out a little better than the 9018 I've burnt so I'd like to go with the 7018, just looking for educated opinions.

 

[Fawteen]

Finally decided to quit waffling around and weld the cutting edge. Clamped the heck out of it, started pre-heating 2-3 inches at a time with my torch and welding it.

Going great, got about 5 equally-spaced stitches, went to heat the next spot and ran out of acetylene.

Gah.

Going good tho, no strange noises or popped welds.

 

[Anonymous-0]

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.

 

[Anonymous-0]

If the grader blade has holes you could also use bolts in addition to welding or just use bolts. Lots of skid steer and larger loader buckets use bolt on edges so they're easy to replace.

 

[Puddles]

jokers my only experience with T-1, is T-1 to T-1, as in repairing fork lift forks, and very heavy duty low boy trailers. I always used 11018, with pre-heat, monitoring inter-pass temperature, and post heat. If someone told me to use 9018 to weld T-1 to mild steel, (or a little higher carbon steel) who has done it before, I sure wouldn't argue the point.
One time I seen a guy splice an I-beam with 11018, it cracked right down the fusion line before he finished. You can push the limits of the steel with 90, and 11018. I've never had any trouble, or heard of anybody having trouble with 8018 on mild or a little higher carbon steel.

 

[Fawteen]

Well, I decided to jump in. No tempstick available locally, one place can order it in and I'll sure get some for future reference.

I'm preheating with my torch, just until the hard steel starts to discolor and turn slightly bluish, and then laying a bead of 7018 in. One stick will weld 4-5" so that's what I'm doing.

Getting a very little pinholing in the bead right at the start of the weld, going to try wirebrushing just before welding to clean it up a little better. Other than that, I'm happy with the progress, and I'm not seeing/hearing any cracks as it cools.

 

[Puddles]

“Getting a very little pinholeing in the bead right at the start of the weld”
Did you put your welding rods in the oven?

I gave up on tempsticks years ago, you can buy an infrared thermometer for $30.00 to $40.00.

 

[Ken-Pa]

Can you send me the URL or link to that particular site ? I"d like to check it out. God bless

 

[Fawteen]

Nope, but they live in a heated cabinet (old metal first aid box with a 40 watt bulb in it).

I'll try pre-heating the rod tomorrow. Getting SWMBO to permit welding rod in her oven might be interesting..."8^)

 

[Fawteen]

Both are right here on YT. Check the "Another Forum" pulldown list at the top of the page for "Tractor Tales" and "Tractor Talk".

You might also be interested in my other site, Shopbuilt. It's one I host for general shop projects, advice, questions, sources and horsing around. See the link
Shopbuilt

 

[trucker 40]

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.

 

[PKurilecz]

looks great ... I hope it lasts a long time ...

 

[Anonymous-0]

If you have a propane BBQ, you could put the rods in there or put a higher watt bulb in your cabinet. It is somewhat common to get porosity at the start with cold rods/steel on higher carbon or dirty steel. You could always strike your arc about a 1/2" ahead and once the arc is established move the rod back and weld over where you struck the arc.

 

[Anonymous-0]

When attaching, or re-attaching cutting edges I used 1/8" 7018. Time and time again. Without preheat or any other particular mentionable concern.

Time and time again. Different buckets, different edges.

No issues.

Tack it.
Stitch it.
Weld it.

On rare occasion I might have bumped up rod dia., but 1/8" 7018 with multiple passes was normal without concern.

 

[Stan in Oly, WA]

Hi Puddles,

Lincoln Electric says, "Several hours at lower temperatures is not equivalent to using the specified requirements." The specified requirement for 7018 is one hour at 650 to 750 degrees F. Lo-hy rods higher than 7018 require higher temperatures.

Of course, proper storage of low hydrogen rods is supposed to be at 250-300 F, and no refrigerator with a light bulb in it is going to come close to that, so redrying at too low a temperature is probably beside the point.

What it amounts to is that nobody who has to use old 7018 and doesn't have a rod oven is going to be welding bridges or skyscrapers, repairing giant earth moving equipment, or have their work subjected to x-ray inspection.

My advice is to pray that the welds done with compromised electrodes will be okay. It's much faster than other things that don't do any good, it feels like you're doing something, and it can't hurt.

Stan

 

[Puddles]

OK, Stan I read your post 3-times, and I still don't get it!

Are you lecturing me on the proper storage of 7018? :?

 

[Stan in Oly, WA]

What is it you don't get? It bothered me that your advice contradicted what Lincoln Electric says about reheating their 7018. You're one of the few people on this forum whose advice I invariably feel is entirely dependable. Maybe other brands of 7018 can be reheated adequately at temperatures a kitchen oven can reach by being left in longer. Lincoln specifically says that theirs can't.

My other point was that most people who aren't weldors by trade are using 7018 in situations that won't be inspected by a certified inspector, and won't be x-rayed. There are so many things to know about a proper weld that the non-professional will not even be aware of, that the effect of less than perfect electrode storage is going to be insignificant anyway.

Stan

 

[GeneMO]

I weld with whatever rod I think will run well. If It breaks I fix it. If an inspector shows up, I will shoot him, that is if he dont run to fast. I never could hit a running target.

I did kill a running deer once, but upon examination he had poked his eye out on the side I was shooting from, so basically I shot a blind deer.

Gene

 

[Puddles]

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.

 

[jokers]

HAHAHAHA! Good one Gene!

 

[jokers]

Thanks for the insight Puddles. FWIW, the cutting edge that I am welding will be T1 to T1. I have 11018 available, I suppose that I should use it. Can you recommend Pre and interpass temps that I should maintain and what is an acceptable cool down rate?

I use one of those Raytech temp guns with a laser at work, I suppose it's time that I invest in something similar for home. BTW, the girls like it when I point the laser at them, look at the temp readout, and whistle....guess they take it as a compliment, I was thinking a couple of times, darn girl...you're cold! ;-)

 

[trucker 40]

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!!!!

 

[Stan in Oly, WA]

Hi Puddles,

"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.

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.

Stan

 

[Puddles]

jokers I have a beautiful article on how to weld T1, but it's 21-pages long and in a PDF file. If you Google “How to weld T-1 Construction Alloy Steels” I think you'll find it. I scanned this chart for you, it should be a good start. :wink:





Stan anytime you warm up 7018 even just warm to the touch it will run easier.

 

[[email protected]]

Thats exactly right

 

[eastexan]

(quoted from post at 20:35:41 03/09/11)
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).
[b:20d3e30fa0] [color=red:20d3e30fa0]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. [/color:20d3e30fa0][/b:20d3e30fa0]quote]

Puddles, I assume this would mean that if the 7018 rod was out of the original package or rod oven for more than 8 hours, it's basically no better than a 7014 rod?
I'm not dissing 7014 rod. It's one of my favorites.

 

[Puddles]

I really don't know. Maybe they're somewhat equal on single pass welds. Or maybe even thinner plate. But I think on thick plate where multipliable passes are needed non properly stored 7018 can be a big problem with hydrogen embrittlement / hydrogen cracking. When welding thick plate one should really use the proper pre-heat, and interpass temperature control which will help with the HAZ!

Here copy & paste this link, good reading on hydrogen cracking.
http://www.sale-associates.com/newpage2.htm