Weldability test for early to mid-1920's steel 1

[PEinc]

thread725-167138

unclesyd,

In the referenced thread, you stated, "A quick test to see if it is readily weldable is to make a one side fillet weld,7018 electrode, a 1/4" 2"x2" tab in an inconspicuous place and try to forcibly remove it.
Try first in the hard direction, hitting one time on the weld side. Then hit it from the easy side. It shouldn't break out the hard way. The weld should fail hitting from the easy side."

This sounds like the same test recommended by AISC. However, AISC does not give a very good explanation of the test. Can you please provide a little more detail for this test. Such as, how hard is hard enough for hitting the plate? Is it better to use E70 or E60 electrode? Hard direction is downward? Easy direction is upward? Please explain why a good weld should easily break when hit from the easy side. Is there anything special to look for when the weld has failed when hit on the hard side?

http://www.PeirceEngineering.com

 

[Duwe6]

Your Carbon and C.E. are excellent. Use a little preheat - 125 to 200F and E-7018 rods. It looks like you have excellent quality steel.

Yes, 6010 is very good for rust & paint. Problem with that is, why do you want to encourage the welder(s) to weld thru garbage?

The weld prep needs to be bare, shiny metal. If they grind a little deep removing the rusty bottom of the pits, it doesn't matter 'in the real world'. They will be welding in that spot -- they can replace the metal that got ground off. The added time will be too small to measure.

If you are supervising the welding, just tell the welder to preheat with a torch "until the moisture comes out". This means that he heats the steel until the condensation ring from the torch combustion [hydrocarbon + O2 = CO2 & H2O] goes away. That is the standard "field term" for a little preheat.

Not that you need it now, but Good Luck.

 

[PEinc]

Thanks for your comments.

http://www.PeirceEngineering.com

 

[unclesyd]

http://www.lawsonproducts.com/webap...934&catpath=All+Products////UserSearch1=00321

 

[unclesyd]

A power spike and brown out let me over click. These excursions used to be blamed on squirrels trying to eat a transformer, now it's the Cu thieves shorting things out.

The link in my previous post to Lawson Products is for their Cratering 321, not SS, CS welding electrode for dirty steels. It is a little expensive but is well worth the price on some jobs to minimize the prep needed. Your welders will love it if used for nothing but the first pass. You will not have to worry about having any leftovers as these electrodes have legs when it come to welders.

 

[PEinc]

Thanks for the link. Don't think I will need it though. The steel is very clean and was covered since being erected.

http://www.PeirceEngineering.com

 

[gtaw]

The sulfur is on the high side. Select an E7018-H4 electrode that contains a manganese content that is at least 10 times greater than the sulfur content and all will be good.

The preheat can be determined using the chemistry you have by referring to Annex I of AWS D1.1-2006, 2008, or 2010. Assume a hydrogen level of H2 (not the same as the H4 hydrogen designation used in the electrode classification E7018-H4). H2 is simply an assumption that the contractor will be using electrodes straight from a hermetically seam tin or from an electrode holding oven within 4 hours (limited exposure time). You can also assume a highly restrained joint condition. Be warned that the carbon equivalency formula used in Annex I is different from the one cited in your post.

Using Annex I (AWS D1.1), the steps are as follows:
1) Determine Ceq using the chemical analysis obtained for the sample
2) Assume hydrogen controls to be H2
3) Use table to select the appropriate column to use in the preheat table
The Ceq is listed along the top row, hydrogen control is left vertical column
4) Next page, looking at the preheat table, left column is the level of restraint (high restrain is most conservative), next column is the base metal thickness, moving along the top row, select the letter selected from the first table (, A, B, C, D, or E, with E representing the highest Ceq.).
5) Move down the letter column until you intersect the level of restrain and base metal thickness – Presto! The recommended minimum preheat is listed!

Note: Not all E7018-H4 electrodes are created equal. Most manufacturers make several types of E7018, each with slightly different chemical compositions. The trick is to ensure the manganese content is at least 10 times that of the sulfur to ensure the sulfur will react with the manganese instead of precipitating to the grain boundaries and causing troublesome hot cracks. Your WPS should list the specific welding electrode by AWS specification, classification, manufacturer, and brand name so the erect knows exactly what you require him to use. Allow no substitutions unless the erector can show you the minimum manganese content of his electrode is at least 10 times the sulfur content of the steel being welded.


Best regards - Al

 

[gtaw]

Editorial Correction;

Sulfur looks fine, but always check the manganese contained by the electrode used.

Sorry for the slip!

Best regards - Al

 

[unclesyd]

If you are having trouble with jacking and holding the load You might want to give Superbolt a call and ask about using a Superbolt upside down as a small foot jack.
I've some some very small ones with 325 ton capacity.

http://superbolt.com/index.php

 

[PEinc]

Update: The contractor welded the steel brackets to each side of the old column. They jacked the column until it moved about 1/16 inch upward. They waited and monitored the column. It did not settle back. They tightened the two lock-nut jacks and continued monitoring the column for a couple more days. Still no movement. The contractor cut off the bottom of the steel column and demolished the pyramid-shaped column footing. The column is now supported temporarily on 4 micropiles, steel framing, and two lock-nut jacks. Everything went smoothly. The column had about 60% of the load that I designed for (no snow load, less than full LL). Monitoring continues.

http://www.PeirceEngineering.com

 

[unclesyd]

Appreciate the update.

It is always good to see a plan come togather.

PS:

Glad you didn't have the column jacked up when the Earthquake hit.

 

[PEinc]

The column WAS jacked up and removed before the earthquake hit. No reported problems.

http://www.PeirceEngineering.com

 

[PEinc]

Here's a picture taken after jacking the column, but before column removal and footing demo.

www.PeirceEngineering.com

 

[Duwe6]

Thanx for the photo. I hadn't seen that style of riveted column before. I would 'guesstimate' pre 1900. Am I anywhere close?

 

[PEinc]

1924 plus or minus.

www.PeirceEngineering.com