How do you handle a HAZ?

Gunner:

Is there enough material to bandsaw off? If so, you could use a die grinder to grind a place for the bandsaw blade to start and cut through, then keep the blade in the unhardened stock. If milling is the only option, conventional milling (not climb milling), often lets you get under the worst of the hardened scale. It's going to beat up your tooling no matter what so using inserted tooling is probably going to be cheaper than burning up high dollar end mills.

All in all, your shaper may be the cheapest way to go.

Shaper? What the hell is a shaper? Kidding. Sort of.

"How do you guys handle working with a HAZ on plate?"

I have some old end mills that are "used up" on the first .100" but are sharp above that. I save these for this kind of thing. I'd cut it with the side, not the end.

Conventional type milling deeper than the worst of the HAZ. I might use an old junk 1/2" carbide at 500 RPM at 5 IPM with flood coolant. I know, that's moving really slow, but that's how I do it.

The worst HAZ I've ever seen was some very thick plate that was cut with a carbon arc. I took a grinder to the bad areas first.

I have an old ceramics kiln that I use to anneal flame cut steel. So far the normal cool down in the sealed kiln is slow enough. It's probably more of a normalization that a true anneal but it's good enough.

Kelley

Interesting. What temps should I run up to? I have a furnace.

Gunner

"A prudent man foresees the difficulties ahead and prepares for them; the simpleton goes blindly on and suffers the consequences."

- Proverbs 22:3

Have you tried a indexable facemill? I never use an endmill for squaring blocks - only facemills. With hardened stuff, I find carbide works well as long as you slow it down. You're good if you've got one that takes cheap inserts.

I was thinking along the lines of Karl with the disc grinder, but .09" is a lot of material and it's very labour intensive to hog material for a long time.

Regards,

Robin

Just throw the whole chunk into the woodstove or burn pile--and let it cool down back down with the ashes, pick it out the next day.

"Gunner" wrote>

My Tempil Basic Guide to Ferrous Metalurgy shows a normalizing temp of about

1600 F. for steel with 30 points of carbon. 4130 normalizes in still air, very still air, don't let the cat wag his tail near the cooling piece and don't fart. A full anneal can be had by very slow cooling in the furnace. The stuff will cut like butter then and will need to be re-hardened after machining. Good luck.

Actually..no..I dont have such a facemill. I havent been able to scrounge up one and a supply of inserts. A fair and dimenishing number of carbide facemills that are cemented..and no way to resharpen them. And with material like this...I dont want to use any more up.

Yup. Thanks for the advise

Gunner

"A prudent man foresees the difficulties ahead and prepares for them; the simpleton goes blindly on and suffers the consequences."

- Proverbs 22:3

Wish I had a woodstove. But this is Central California desert.

I do have a kiln though..small one..big enough for heat treating. What temp should I get it up to?

Gunner

"A prudent man foresees the difficulties ahead and prepares for them; the simpleton goes blindly on and suffers the consequences."

- Proverbs 22:3

So if I stack em up, and hold em at 1600 for a couple hours..then turn off the juice and leave em in the oven..it may anneal them.

Thanks, Ill try that as my second option

Gunner

"A prudent man foresees the difficulties ahead and prepares for them; the simpleton goes blindly on and suffers the consequences."

- Proverbs 22:3

4130 anneal: heat to 1600F, cool to 1255F @ 20F/hr, cool in air 4130 normalize: heat to 1600F, cool in air

Ned Simmons

Bonfire?

Gunner:

==========================================================

Annealing 4130 (and most of the other low alloy steels) may be annealed at 1550 F for a time long enough to allow thorough heating of the section size. It should then be cooled in the furnace at a rate of less than 50 F per hour down to 900 F, followed by air cooling from 900 F. ==========================================================

What type of endmills were you using?

Go to

and put 3460 in the search box to go to that page, then click the link at the top for additional info. This gives composition and physical properties for most common steels, and heat treating data on the tool steels (but not 4014, big sigh ;-)). Then put

3464 in the search box and repeat to get data on stainless steels. Again, they give annealing data for most alloys but not for 17-4 and 17-5 PH, again, big sigh. Anyway, a useful grab for the future. Hold times at temperature seem to be 1 hour per inch of thickness. This assumes good heat circulation and if you stack your plates directly on each other they will look like one really thick plate. Put some little spacers in between each plate so the air can circulate.

-- Regards, Carl Ijames carl.ijames at verizon.net

You have to use aids to avoid big attacks of 'Can't Remember Sh*t' like that. Do you have any programmable timers or an old Lux wind-up kitchen timer around? Or use a good old (loud) alarm clock that will not quit till you turn it off...

If you figure it's going to need looking at in an hour, set the alarm for an hour. And set up a second alarm at two hours in case you miss the first. If you figure it needs looking at before you go to bed, put something big and heavy on the bed - when you go to move it, you'll remember.

(And tell the wife/roommate/kids why you are setting the alarm, so they know not to just turn off the alarm without finding you.)

And in the end... It was already scrap material when you started. So what did you lose, except some electricity running the kiln? ;-)

If they did warp into interesting shapes, you can always weld them into a sculpture, let your muse loose.

-->--

I try putting things in conspicuous places to remember things to do and my wife puts them away. A couple of weeks later I'll remember (maybe).

-- Randy Replogle

I've found that relationships are like a bell curve. You love a few, hate a few, but most you're just indifferent to.

-- Randall Replogle 2006

I think next time..Ill fire the oven up without anything in it..fiddle around until its the proper temperature..THEN load it. It will sag of course..then slowly return to the proper temp..and I can go from there

Still pissed me off.

Gunner

"The importance of morality is that people behave themselves even if nobody's watching. There are not enough cops and laws to replace personal morality as a means to produce a civilized society. Indeed, the police and criminal justice system are the last desperate line of defense for a civilized society. Unfortunately, too many of us see police, laws and the criminal justice system as society's first line of defense." --Walter Williams