A neighbor's friend brought a small welding repair over for me . It's an I beam that is the backbone of a PTO powered post hole auger . But that's not what this post is about , this post is about OHMYGAWD I love my new welder . The flange that carries the yoke that the auger hangs on had fatigued and split from the web , First order was to pull it back into position and tack it in place . Then vee one side and run a bead then flip and grind down to fresh weld and lay in a couple of passes - all on the lowest power setting . Welding 1/4" thick reinforcing strips on both sides had it all the way up to half power . I may never need to use my tombstone welder again ...
A neighbor's friend brought a small welding repair over for me . It's an I beam that is the backbone of a PTO powered post hole auger . But that's not what this post is about , this post is about OHMYGAWD I love my new welder . The flange that carries the yoke that the auger hangs on had fatigued and split from the web , First order was to pull it back into position and tack it in place . Then vee one side and run a bead then flip and grind down to fresh weld and lay in a couple of passes - all on the lowest power setting . Welding 1/4" thick reinforcing strips on both sides had it all the way up to half power . I may never need to use my tombstone welder again ... Snag
I've been debating selling mine. On the rare occasion when I really might need to burn some 7018 for some thicker plate I have the AHP ACDC Pulse TIG/Stick. I like running DC stick so much better than using the AC cracker box.
I've got a lincoln AC/DC "tombstone" and it's plenty heavy enough for anything I do - sure like the DC capability. Don't have occaision to use it much as it's a bit TOO big for some od the stuff I've been into lately where I have a buddy TIG for me
Yup , the roll this welder came with when it was brand new . I never realized how handicapped that WeldPak 100 was ! I was going to set it up for .030 solid wire for this repair , but there was enough of a breeze today that flux core was a better choice .
Mine's probably worth more as scrap ... I've read that these IGBT welding machines have a bit of a different current profile , had mine for several years now and I've never even plugged the stinget cable into the machine . My stick welding sucks and I avoid it when I can .
Mine's probably worth more as scrap ... I've read that these IGBT welding machines have a bit of a different current profile , had mine for several years now and I've never even plugged the stinget cable into the machine . My stick welding sucks and I avoid it when I can . Snag
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I was terrible at stick welding until I took a night school class in it and was shown the proper preparation and technique, and introduced to 7018 DC. I spent all 6 sessions practicing making and breaking welds until finally I could fold one double without a crack. Then I built the front end loader and sawmill.
It was just as helpful and more economical of steel to run many parallel beads across one piece of randomly shaped steel scrap instead of joining two straight-edged pieces.
I did that with the TIG . I should do a sheet or two with the stick , I may be able to do better now . I've been studying puddles ... and it helped my MIG welding , may be it could help with stick too .
That's the almost universal story of learning welding - starting off as a basic but competent welder-the-person, isn't it?
Doing "pad-welds" is a great start. When you can lay a neat pad (which you might do "in real life" - build-up a worn section of a machine), you probably control angles (tilt and slope), run-rate, where exactly you are pointing the rod - so "you know where you are going with it" you have the basics of depositing metal. Well to be commended.
Then making-and-breaking welds - that learning cycle. Makes you "engineering-minded". You are visualising a weld which will do the job and doing it. I worked in a college in a terribly deprived part of London and also did welding training there, and I can tell you - the welding school is always an oasis. If you went in and saw any person and asked what they are working at, they'd show you "the next weld" they are trying to master, how they have improved, what they think will get them there and what their hope is "I'm hoping to have 'got it' by midday meal break / by afternoon tea-time / etc. All on their own mission. (unlike a classroom where you are trying to get a cohort along one shared learning path). The self-motivation is astonishing in a welding school, compared to the miasma of hopelessness which can be most of the rest of the place.
"Don't make welds without breaking welding" is the root.
Here in the UK in production environments if that had that principle in mind most of the problems would not be there. As I have seen.
In education to fit "frameworks" (sic.) they have split up years into "appearance" and then "doing breaks and macros". Never do that - the advance is fine-scale evolution make-and-break (and macro).
So - big yes, yes, yes, concurring that is exactly the way and so it is that it was so for me.
Regards, Rich Smith
Welding is complexly dependent on several physical Laws of the Universe, unless a situation is so familiar and you know how good and bad welds run, you really should be doing test-welds.
Then what you mention next - the problems I have seen in the UK if they did this most basic thing they'd get out of those problems.
So - big yes, yes, yes, concurring that is exactly the way and so it is that it was so for me.
Regards, Rich Smith
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I didn't realize how hide-bound the educational establishment was until I started taking night classes with teachers who worked for a living. Instead of worshipping the formal structure of, say, Calculus they taught it as a useful tool, and finally I could understand it. In the college textbook the Limit process that underlies differentiation and integration took up one paragraph. The night class spent two weeks on the Limit origins of the memorized formulas and then they made sense. A useful trick I learned was memorizing reciprocals, which enables mental division and simplifies setting up a lathe to cut screw threads. Afterwards I could solve questions of frequency, capacitance and inductance in my head before the engineer could find his calculator.
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" ‘Pure’ scientists were often more disparaging of applied science than the other way around. This kind of scholarly rivalry has been around since the ancient in-fighting between classical philosophers. John Dewey (among others) saw it as simple class snobbery:"
I see it as denying the value of what they aren't good at. An article I read about Los Alamos mentioned a camping trip which revealed that many of the world's top theoretical physicists couldn't light a fire. The author was the only physicist who could weld, and thus quickly fixed many problems the others would have sought a consultant for -- a considerable delay on a highly classified project.
The local night schools have been lucky to find excellent nuclear and bridge certified welders who could also teach. They have more trouble finding qualified instructors for the other subjects they would like to offer such as small engine repair, so much that they asked if I was interested. There are too many gaps in my self-education for that. I took the auto repair course to learn what's new and maybe lose any bad habits I'd acquired. jsw
Doing "pad-welds" is a great start. When you can lay a neat pad (which you might do "in real life" - build-up a worn section of a machine), you probably control angles (tilt and slope), run-rate, where exactly you are pointing the rod - so "you know where you are going with it" you have the basics of depositing metal. Well to be commended.
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On my own initiative I practiced filling in coin-sized holes with MIG and piling up aluminum stalagmites with TIG, to refine my puddle control. I think they were good practice though I haven't seen them recommended.
Yes I met this teaching vocational students. Showing them the theory and maths is actually good and useful.
I can barely understand a word of mathematics books for techniques I have "re-invented" and used given a need.
When doing my welding engineering masters the two of us who were welders - the poor Head of Department would rather have endured an untreated case of an embarrassing socially transmitted condition than have to talk with one of us.
Poor fellow!
The thing is we - the two of us welders - often knew that things don't work the way he was trying to help us see the way to proceed. Also some welding conditions are so exact that you have to know they are there and recognise your way to a very exact condition a matrix of test conditions could never find (the combinations are unimaginably immense). There were all sorts of things where we knew "God's design" and were therefore respectful of it. eg. response "If you as much of think of iron and titanium in the same thought they form a brittle intermetallic phase" Obviously that is superlative, but the direction of the conversation can be inferred :-)
But yes the poor fellow thought his esteemed theoretical science was superior to our "applied science". Oh gawd - the poor fellow threatened to walk out of a meeting after I explained a strategy he suggested would not work - until he looked around and realised we were in his own office - he'd threatened to walk out of his own office ...
"Don't make welds without breaking welding" is the root.
Here in the UK in production environments if that had that principle in mind most of the problems would not be there. As I have seen.
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I've been testing things to destruction since high school, on a Tinius Olsen tensile strength tester at an after-school factory job. I destroyed a prototype GM fuel injection computer by subjecting it to the overvoltage abuse it was supposed to withstand, on a machine I built to their specs.
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I don't know if the 40V spec applies to welding, I disconnect the battery just in case. The energy in a load dump is whatever was stored in the alternator rotor's inductance, not continuous like a welder, although it can repeat, so my machine had time delay relays to let them set the pulse repetition rate. They specified a maximum time that included their undisclosed intended setting.
At the time, the mid 70's, electronics was new to the automotive industry which previously had nothing more complex than a radio they bought. They hired a lot of bright new electrical engineers who had to painfully learn the decidedly non-theoretical conditions of road vehicles and typical American lack of maintenance. I did have the slight advantage of coming from military electronics which have to take anything Nature throws at them, though at a commercially unacceptable cost and weight penalty.
----------------------------- Chemistry was different, the theory had evolved to explain unexpected experimental results. Newton had been able to puzzle out the underlying principles of Physics, Optics and Calculus but he utterly failed with Chemistry. The last critical step came in 1932 with Chadwick's discovery of the Neutron, which finally explained why many elements didn't have the simple integer atomic weight relationships the prevailing theory predicted.
I didn't encounter pure theoreticians outside the classroom until later and by then I knew enough to deal with them. One Ph.D didn't know that resistors come with tolerance bands, he expected 8 digit precision until shown the commercial reality, and he didn't know how to handle measurement uncertainty as chemists have learned to. His final product had a 40% tolerance.
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down to 0.01% are available if you need and can afford them. When I was building industrial test equipment in the 1980's they were $5 each, standard ones were $0.10 or less. Any that we drew from stock for lab use became "tainted" and couldn't be returned, so I have a decent supply of lightly used ones to calibrate my meters since I was building and programming the test and calibration fixtures.
At Mitre the pure theoreticians apparently knew better than to try to design actual hardware, so the Ph.Ds I worked for had practical experience. I still could think of simplifying shortcuts they hadn't, to the extent that they handed me data sheets for the critical components and left me to figure out how to use them.
There were all sorts of things where we knew "God's design" and were therefore respectful of it. eg. response "If you as much of think of iron and titanium in the same thought they form a brittle intermetallic phase" Obviously that is superlative, but the direction of the conversation can be inferred :-)
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Huh?
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"By far the most important use of titanium is in making alloys. It is the element most commonly added to steel because it increases the strength and resistance to corrosion of steel."
It may be like the effect of manganese in steel and depends on the percentage, see
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also known as Hadfield steel. It mentions as I remembered that around 5% - 6% manganese addition it becomes so brittle it can be pulverised with a hammer beyond that things change and it becomes extremely durable and abrasion resistant. I may have some as I have an ore crusher knuckle somewhere.
It may be like the effect of manganese in steel and depends on the percentage, see
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also known as Hadfield steel. It mentions as I remembered that around 5% - 6% manganese addition it becomes so brittle it can be pulverised with a hammer beyond that things change and it becomes extremely durable and abrasion resistant. I may have some as I have an ore crusher knuckle somewhere.
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Tin bronze is like that, at a 2:1 mix it's quite brittle.
My impression is you shouldn't place too much credence on the "jrank" link.
The brittleness is any attempt to bring together a piece of titanium and a piece of iron/steel.
Alloying - broadly (forgive me experienced steel metallurgists) Titanium as an alloying addition is one of the very reactive alloying elements usually used in small quantities, like Aluminium, Calcium, Niobium, etc. With an already "clean" melt, Titanium is a ferocious "getter" for non-metallics in the melt. Titanium reactant precipitates feature in grain-refining. It might feature in a super-refined melt going to a High-Strength Low-Alloy steel - eg. a Thermo-Mechanically Controlled-Processed steel (see Dillinger Huette and the few others in the world (?) who can do this). I guess that throw Titanium in a "rough" melt and it would be entirely consumed and lost "getting" oxygen which could be much more cheaply removed with Aluminium.
Get someone who works with this stuff to comment if it's important to you.
In Sheffield there was an alloy with a small Titanium addition and it was a few Rockwell hardnesses above what it should have been. If they could have understood where it came from and what its characteristics were it would have been a very cheap way to get a stronger harder steel, if all else were well. I had a go at it - it would grain-grow if left a long time at a high temperature, so that eliminated some hypotheses at what was going on. Etc.
I am not completely without knowledge, but do get experienced advice if it matters.
Having been looking at your website and in particular at your thesis recently... yeah, I can tell. I mean, that "sixth-jumping" technique of numerical computation is brilliant. One could probably derive it from the partial differential equation for diffusion (in a derivation that would involve making approximations at various points), and that would be theorists' way of doing it. But you just pulled it out of your hat, as if it were obvious, which in a way it is. It's not the most efficient way to do the computation, but it will do, and is simple and direct. (If you ever have that task again, look for a heat equation solver and pretend hydrogen content is "heat", the heat equation is the same as that for diffusion.) In any case, a theorist would have made it sound more profound, but wouldn't have done it any better -- at least as regards the core algorithm.
On the other hand, your treatment of boundaries between regions with different diffusion coefficients really could have used a theorist's input, because the first thing to decide from a theoretical perspective is what the boundary condition should be. And the usual boundary condition for diffusion is that the concentrations on each side of the boundary are equal -- whereas you looked at your algorithm, whose process resulted in (at the boundary) a sharp jump in concentrations, and took that as given. It's not; you have a clever hack for changing the diffusion coefficient that works fine on either side of the boundary, but that hack should not be taken as an inevitable statement of what happens at the boundary. There are other possible hacks, such as changing the cell size on the slower-diffusing side to be smaller, which would give no jump.
Sometimes there can indeed be a sharp jump; for instance if one side has a greater chemical affinity to the thing that is diffusing, then there's an energy level difference across the boundary, and since it's harder to go uphill than downhill the result is a jump in concentrations. But in this case that seems unlikely since you still basically have steel on both sides of the boundary: a hydrogen atom that wanders across the boundary won't find much change in conditions. (On a basic physics level, the diffusion can't be purely a process of jumping from one site that traps hydrogen to another; there's got to be some wandering-around between such sites, and it's the wandering-around that determines what site it lands in.) A sharp jump in concentration can't absolutely be ruled out, but shouldn't be assumed, either.
This doesn't affect the main results of your thesis, of course. I was reading it because although I'd heard of hydrogen embrittlement, the fact that hydrogen actually could be observed bubbling out of a freshly welded surface (under the right conditions) was new to me and intriguing.
Anyway, learning the theory of partial differential equations well enough to use it takes a lot of time and effort, and no one can be blamed for not doing so (unless of course that's what they're being paid for).
"Their minds bred in and in, and were accordingly cursed with barrenness and degeneracy. No extraneous beauty or vigor was engrafted on the decaying stock. By an exclusive attention to one class of phenomena, by an exclusive taste for one species of excellence, the human intellect was stunted."
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