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Old 04-15-2021, 05:22 PM
John in WI John in WI is offline
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Default Porosity in hardfacing welds (SMAW)

Hi Guys, I got the fabrication of my anvil finished. I'm working on the last step--hard facing the surface. After discussing it with an engineer at Lincoln, they suggested laying down a couple layers of Wearshield BU (BU for buildup), to help the transition from soft mild steel to hard steel. Over that I'm going to lay Wearsheild 15CrMn.

Unfortunately, I'm having a bugger of a time welding with the BU. I've been getting a lot of porosity. The original steel was freshly cut with a saw. Perfecty clean. I opened the package of rods--they were brand new.

So I was trying to lay stringer beads, then alternate to the other side. Stop, chip/pien the surface, wire brush, then weld some more. But some of the regions have areas with serious holes in the flux, and usually also in the steel.

I've never had this problem with 6011, 6013, or 7018s.

What are some common causes for porosity in stick welds, assuming everything is clean enough? I would say it's because of improper cleaning between beads, but it happens even if I weld on a clean test piece.

thanks for any info. I have a lot of grinding and drilling ahead of me unfortunately
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Old 04-15-2021, 06:41 PM
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Try not to breath those fumes from that rod. The only thing I can think of as long as your heat and polarity are right it might be ark blow, try moving your ground.
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Old 04-15-2021, 10:18 PM
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Quote:
Originally Posted by John in WI View Post
Unfortunately, I'm having a bugger of a time welding with the BU.
I've been getting a lot of porosity. The original steel was freshly
cut with a saw. Perfectly clean. I opened the package of rods --
they were brand new.
1. Do they have to be dry like 7018 or other low hydrogen rods?
2. Are they dry?
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Old 04-15-2021, 10:26 PM
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Reverse or straight polarity?
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Old 04-16-2021, 06:35 AM
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Quote:
Originally Posted by John in WI View Post

Unfortunately, I'm having a bugger of a time welding with the BU. I've been getting a lot of porosity. The original steel was freshly cut with a saw.

What are some common causes for porosity in stick welds, assuming everything is clean enough? I would say it's because of improper cleaning between beads, but it happens even if I weld on a clean test piece.

Don't assume anything- make sure.
Arc length too long- air con get into an arc with too long an arc length


Dry your rods anyway,100 degrees C for an hour.I think thats 212F in American money.

Wrap up in aluminium foil and put them in your oven- when wife is out

Change polarity if you are on a DC welder.

Clean down steel with a solvent and a rag- take obvious precautions there before welding again.

Ozwelder
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Old 04-16-2021, 07:13 AM
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How about some pix of the porosity ?
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Old 04-16-2021, 10:28 AM
John in WI John in WI is offline
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Thanks for the suggestions. I know breathing welding smoke is bad news--I can't imagine Manganese and Chromium smoke are good for you. We have a big and efficient smoke extractor.

I'm running the rods on AC (Lincoln specs say that's ok).

I think what I need to do is grind the surface down to nice stable metal, and spend a lot more time practicing on scrap. I was getting to be ok with 60xx and 7014 electrodes, but these hardfacing rods run really strange. I'm wondering if I'm just running too hot. I need to fiddle around with the current and travel speed I think. They are just so expensive, I don't want to burn a bunch up trying to figure it out.
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Old 04-16-2021, 10:46 AM
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Quote:
Originally Posted by John in WI View Post
Thanks for the suggestions. I know breathing welding smoke is bad news--I can't imagine Manganese and Chromium smoke are good for you. We have a big and efficient smoke extractor.

I'm running the rods on AC (Lincoln specs say that's ok).

I think what I need to do is grind the surface down to nice stable metal, and spend a lot more time practicing on scrap. I was getting to be ok with 60xx and 7014 electrodes, but these hardfacing rods run really strange. I'm wondering if I'm just running too hot. I need to fiddle around with the current and travel speed I think. They are just so expensive, I don't want to burn a bunch up trying to figure it out.
I think you need to post some pix.....
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Old 04-16-2021, 02:30 PM
JBFab JBFab is offline
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I agree some pictures may be helpful, but the first thing I would do is switch to DCEP instead of AC. Many rods "say" they can be run on AC, but in my experience they don't run nearly as well on AC (with some exceptions). Switch to DCEP and give it a shot - I'd bet you'll see immediate improvement.
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Old 04-17-2021, 05:16 PM
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Quote:
Originally Posted by JBFab View Post
I agree some pictures may be helpful, but the first thing I would do is switch to DCEP instead of AC. Many rods "say" they can be run on AC, but in my experience they don't run nearly as well on AC (with some exceptions). Switch to DCEP and give it a shot - I'd bet you'll see immediate improvement.
the man speaks truth+1
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