# Removing Stress



## savarin (Aug 8, 2016)

I will be making a couple of webbed angle plates from 12mm hot rolled steel.
They will be welded up with triangular webs.
I realise that the welding will distort them slightly.
Whats the consensus with getting them red hot in the furnace and soaking it for some minutes then allowing them to cool slowly as a means of removing any residual stress that may be in them.
Do you think its even necessary.
They will be faced in the lathe after this by Dave Gingery's method.


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## Randall Marx (Aug 8, 2016)

I would try something similar on scrap material and measure before and after to see how much difference it makes, then apply your findings proportionally to your intended material and project. I would be interested to know what you find.
Good luck!


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## Wreck™Wreck (Aug 8, 2016)

Weld, stress relieve then finish machine.

http://www.efunda.com/processes/heat_treat/matl_modify/stress_relieving.cfm


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## Ulma Doctor (Aug 8, 2016)

thanks for the link Wreck!


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## Wreck™Wreck (Aug 8, 2016)

You are welcome, once a month or so I turn 304 stainless parts from laser cut sheet that range between 8" and 24" in diameter with O-ring face grooves, counterbores, holes and tapers, some of the features finish at .060" thickness which will not remain flat after machining from a 3/8" plate. Most all of the drawings stipulate flame cut stock stress relieved before machining.


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## MozamPete (Aug 9, 2016)

Buy a few beers and take it out for a day fishing. Best stress releif I've found.


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## pineyfolks (Aug 9, 2016)

You could bolt them together with counter sunk socket head cap screws. Mill a shallow slot for the gussets to set in. I had an angle type fixture made that way.


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## chips&more (Aug 9, 2016)

Maybe try a pneumatic needle scaler


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## 4GSR (Aug 9, 2016)

savarin said:


> .........Whats the consensus with getting them red hot in the furnace and soaking it for some minutes then allowing them to cool slowly as a means of removing any residual stress that may be in them.
> Do you think its even necessary...........


If you put them out in the hot Texas sun we are having here right now, they will be stress relieved in a couple of days!

May I ask how big the weldment will be?


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## savarin (Aug 9, 2016)

The base plate is  100mm square, the vertical face is 120mm high


to become part of this


I have the original angle plate from my first attempt at building a vertical slide (but its not dead square) that uses a soft small cast aluminium slide.
This version is in steel and the larger front slide will have a matrix of threaded holes to allow a multitude of fixtures (I hope)
The base plate is 100mm square so it can fit onto the cross slide in either orientation.


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## Wreck™Wreck (Aug 9, 2016)

Now that I have some idea of what you are trying to accomplish I would bolt that together, 100 MM is less then 4" per side, why would you weld and distort something that small?
You could mill that from a solid piece of cast iron in less time then making the individual parts, welding, stress relieving and finish machining of the weldment.


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## brino (Aug 9, 2016)

Wreck, I believe the point is to make a milling fixture for the lathe. That is, he does not yet have the capability to mill it from solid.

Although bolting it together is a good option.

-brino


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## savarin (Aug 9, 2016)

Sorry Wreck Wreck but unfortunately I have to disagree, I have no mill, no cast iron blocks and cannot afford them.
This is the easiest way I can get any form of milling done.
The first version was a good learning project and now I can make a better more rigid one.
I would love a mill and all the resulting tools but its just a pipe dream.


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## 4GSR (Aug 9, 2016)

savarin,

In a weldment that small, I highly doubt you will have to worry about distortion when you machine it, from experience.  You are using mild hot rolled steel plate, which is very soft, I assume.  The welding is going to generate enough heat to eliminate and stresses induced from welding.  I say weld it up and get after it.  I also suggest to machine the surfaces to near size, then come back and finish the flat surfaces to get them square to each other.

Ken


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## JimDawson (Aug 9, 2016)

I don't think you will have to stress relieve a welded part that small, but I would bolt it together.


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## savarin (Aug 10, 2016)

4gsr said:


> savarin,
> 
> In a weldment that small, I highly doubt you will have to worry about distortion when you machine it, from experience.  You are using mild hot rolled steel plate, which is very soft, I assume.  The welding is going to generate enough heat to eliminate and stresses induced from welding.  I say weld it up and get after it.  I also suggest to machine the surfaces to near size, then come back and finish the flat surfaces to get them square to each other.
> 
> Ken


Thats what I was hoping to hear.


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## Tony Wells (Aug 10, 2016)

A lot to do with stress relief of weldments temperature at which the weldment is done, and the amount of material removed after cooling. Most distortion comes from the fact that the weld shrinks so much as it cools, and "pulls" surrounding metal mass inward towards the center of the weld. And of course metal (most) expands when heated, so if the entire thing is hot to begin with, everything shrinks in all directions and this lessens the localized effect of the weld area shrinkage. 

The other thing is how much material you remove after welding. And of course where in relation to the stress direction created by the cooled weld. Sometimes it is better not to try and clamp everything tightly in a finished position, like trying to hold this angle plate square, because you know that as you weld it, the heat/cool will try to make things move. If you go ahead and let them move, but in the direction you want them to to bring them into a desired position, less post weld stress will be there to begin with. But that's part of the black magic of welding up stuff without much distortion. Lots of educated, predetermined positioning and weld sequence. 

A weldment that small shouldn't really present that much of a challenge in all of this, but you can learn a lot about the effects of different approaches to creating proper weldments. 

Make sparks!


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## brino (Aug 10, 2016)

Tony Wells said:


> A weldment that small shouldn't really present that much of a challenge in all of this, but you can learn a lot about the effects of different approaches to creating proper weldments.



....and @savarin, please share what you do and see so we can all learn. 
I can see needing to build up some parts of similar size and I could use any hints you produce.
Thanks!
-brino


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## savarin (Aug 10, 2016)

no worries Brino, I'm collecting the pics as I go.
I'm also wondering if I can also design in a tilt function although I cant see a need yet.


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## Mark_f (Aug 10, 2016)

Before I got a mill, I had to do my milling on my lathe. I got an 8" square Blanchard  ground steel plate  3/4" thick off eBay pretty cheap. I made a plug to go in it and mount to my cross slide after removing the compound. I drilled a matrix of 3/8-16 tapped holes in the plate. It mounts in just a couple minutes and gives me a nice flat table that I could feed in both directions ( I have cross slide feed on my lathe). I know the height from the table to spindle centerline and shim a part to the right heir an mill.  I can mount a vise on the plate or an angle plate and then put the vise on the angle plate. It works great and is pretty versatile. I still use it once in a while. Just a thought.


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## Wreck™Wreck (Aug 14, 2016)

A weldment that I did several weeks ago, all of the parts were made in a mill, after welding the main structure went back in the mill and the top and bottom surfaces were skimmed flat and the holes reamed as the drawing specified a +.002"-.000" bores.








I have no clue what this thing does aside from the description on the drawing which is "Slag Skimmer", I assume that it is part of a device that skims the slag from the surface of the crucible of an induction furnace used in steel making.


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