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Weldability test for early to mid-1920's steel

Weldability test for early to mid-1920's steel

Weldability test for early to mid-1920's steel

(OP)
thread725-167138: Welding Pre-1920 Steel to New Steel

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?

www.PeirceEngineering.com

RE: Weldability test for early to mid-1920's steel

The test described is very subjective.

Another test that can be used is to obtain a small sample of the steel to be welded and have it analyzed to determine the chemistry of the steel. The following elements should be included in the report and considered before welding is contemplated:
Carbon: <0.3%
Sulfur: <0.04%
Phosphorous: <0.04%

Once you have determined your actual chemistry does not exceed the limitations noted, you can plug the actual chemistry into a carbon equivalency formula to determine the carbon equivalency. There are several equations that can be used. Each equation has its own guidelines and recommendations. I suggest using the method described in AWS D1.1-2006 (or later) in Annex I.
  

Best regards - Al  

RE: Weldability test for early to mid-1920's steel

(OP)
Thank you, but I don't think they will let me cut a sample from the existing 5 story column of this historic building.

www.PeirceEngineering.com

RE: Weldability test for early to mid-1920's steel

Why not remove a 1/2" round plug sample from the original column at the location where a new column will be joined by welding? A hole saw is ideal and would allow for a full chemical analysis.

RE: Weldability test for early to mid-1920's steel


I not against any of the above suggestions but I you can't lay a bead on the base metal the tests above are mute.
I used the welded tab many times and it hasn't let met down yet.  The test is not anymore suggestive than the chemical test proposed. If you actually weld on the subject steel you take out more variables, one in particular is Silicon Stringers.  
As stated make the weld on one side and allow to cool.  It should bend toward the weld without the bead tearing out from the base metal.  If you night want to weld the second tab and try to bend it the hard way,  One other test if there is any doubt is the Navy test which is accomplished by welding a 1 1/2" circle spiraling inward, leaving a 1/2" hole in the middle.
 
Do you see any welding on the column?
 

RE: Weldability test for early to mid-1920's steel

(OP)
No welding is seen.  The column is made of 2 flange plates, one web plate and 4 angles, all riveted together around 1924.  Eventually, the bottom of the column gets cut off and a new base plate is welded to the column. I am involved with picking up the column so that the contractor can remove the footing and build a deep foundation wall under the column.  I asked the CM to ask the project structural engineer if anyone had determined the weldability of the steel.  I got no response.  YET!  So far, it seems that the project engineer has just assumed that the steel is weldable.

www.PeirceEngineering.com

RE: Weldability test for early to mid-1920's steel

PEinc, please do not ASSume that that steel is actually weldable.  It may not be, especially if it has a high sulfer content -- thus the need for a chemical analysis.  A high carbon content can be worked around by using a high 250-350°F continous preheat and 100% E-7018 rods.

The 'gold standard' weldability test is to remoive a paperback-sized section.  Split the section longways, using a saw -- 'cold-cutting' of the split only.  Weld the pieces back togather, using no [ambient] preheat and a less-than 120°F interpass temp.  Perform Face and Root Bends per AWS D1.1 or ASME Sect IX -- both are the same.  If the bends pass, you have very weldable steel.

If not, use a higher preheat on the next test, and pray a lot.

RE: Weldability test for early to mid-1920's steel

You need to determine the carbon equivalent using the IIW formula.  Two options for testing:

(1) Portable spark tester - expensive but almost zero damage.
(2) Remove and collect scrapings using a clean carbide burr.  This is standard practice on buried pipelines.  It can be done leaving not more than 0.020" removal.  

You might be surprised at the quality of the steel.  I once had to repair a 1913 vintage steel on a hydro turbine and it was low carbon and quite weldable.   

RE: Weldability test for early to mid-1920's steel

p.s., on a heavy section of that vintage there may be a significant decarburized layer, so any method would need to allow for that.   

RE: Weldability test for early to mid-1920's steel

(OP)
Duwe6, it appears to me that the only one "assuming" the steel is weldable is the project's SE.  I will not be allowed to remove a paperback-sized piece of the column for analysis, but thank you for the response.  I'll do some research on your suggestions.  The project SE indicated (and then "un-indicated") that this column is supporting 425,000 pounds.  My load estimate is less than 350,000 pounds.  I'm using the larger load.  I can't afford to drop the city's art museum.

brimstoner, I'm not a welding expert so I'll have to look into your two options also.  Thank you.

www.PeirceEngineering.com

RE: Weldability test for early to mid-1920's steel

If all you are going to weld is a base plate and with you specified loading I would that there is no shear loading. I would get to the end where the base plate is going to be attached and try welding small tabs on the ends of the column components.  If it is not weldable there should be no problem clearing the affected area.

Be real careful when clean the column.  I would bet that it has a red lead primer. When you try to weld get the area as clean as possible before attempting to weld.  

RE: Weldability test for early to mid-1920's steel

(OP)
unclesyd, the base plate is the least of my worries.  I am picking up the old column so that the contractor can remove its foundation completely, cut off the bottom of the column, excavate 25' deep in rock, build a new tunnel, and then reset the old column on a new base plate that the project SE designed and wants welded to the bottom of the column.  I need to support 425 kips with micropiles and, hopefully, a welded connection.  The micropiles, steel cap beams, and jacking beams need to be located far enough away from the column to clear the existing pyramid-shaped footing and the new tunnel wall.

www.PeirceEngineering.com

RE: Weldability test for early to mid-1920's steel

Again I may be missing something.

Will all the welding required be on the base plate to column connection?

RE: Weldability test for early to mid-1920's steel

(OP)
I do not know how much other welding is required for the existing steel on this project.  I am involved only with temporarily supporting this one column.  The base plate is not in my scope of work.  There is much more work involved in converting this basement area into useable museum space.

www.PeirceEngineering.com

RE: Weldability test for early to mid-1920's steel

(OP)
FYI, here's the latest:

My client hired a company to come in and analyze the composition of the steel in the 1923-ish riveted column.  The company did a Positive Material Identification (PMI) Test.  According to the testing company, "The material has suitable alloying and iron elements to be categorized as a weldable material..."

The analysis-by-weight showed:
ZN - 0.01%     MN - 0.37%
FE - 98.48%    ZR - 0.01%
PD - 0.03%     CU - 0.32%
NI - 0.18%     CR - 0.05%
TI - 0.49%     AG - 0.04%

Their recommendation is to use E6010 rod for pitted and dirty areas where the base material cannot be completely prepped/cleaned and E7018 rod where surface preparation can bring the base material to an "as new" condition.  The company will be on site to inspect the welding when the work is being performed.

Thank you for all of your comments.

www.PeirceEngineering.com

RE: Weldability test for early to mid-1920's steel

The problem with the PMI analysis results above is it only types the material. There is no carbon content, phosphorus or sulfur contents reported, which would have a direct impact on weldability of the steel. Oh well....

RE: Weldability test for early to mid-1920's steel

And it takes very little sulfur to make it unweldable.  I strongly recommend that you use the 'Spark/Plasma Test' PMI method, or send in some metal shavings for Mass Spec analysis.  I agree with Metengr that it appears that your PMI was done using XRF -- x-ray fluorescence, thus did not test for C, P, Su, or any other light element.

In short, I would not stand anywhere near that column when it was cut without ANYTHING definitive for weldability.  XRF is good for sorting 304 and 316 stainlesses, Hasteloy, etc. and determining the chrome content of carbon steel.  It tells you nothing about the weldability of carbon steel.

RE: Weldability test for early to mid-1920's steel

metengr,

I have given up trying to disabuse owners and inspection techs (and a few inspection engineers!) of the notion that PMI provides a chemical composition.  People see two decimal places on a sophisticated looking display, believe them and then report them.  

'Oh well' is right ...

RE: Weldability test for early to mid-1920's steel

(OP)
Thank you both.  I will pursue this farther.

www.PeirceEngineering.com

RE: Weldability test for early to mid-1920's steel

(OP)
FYI, I just got the results back from testing a steel sample using 86-SCA-0, Rev. 11, Direct Reading Atom Emissions Spectroscopy.

Al = 0.011%  B = 0.0004%   C = 0.20%   Cr = 0.008%  Cu = 0.016%
Mn = 0.42%   Mo = 0.012%   Ni = 0.031% P = 0.006%   S = 0.021%
Si = 0.007%  V = 0.001%    

CE = 0.2785 = C + (Mn+Si)/6 + (Cr+Mo+V)/5 + (Cu+Ni)/15

www.PeirceEngineering.com

RE: Weldability test for early to mid-1920's steel

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.

RE: Weldability test for early to mid-1920's steel

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.  

RE: Weldability test for early to mid-1920's steel

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

www.PeirceEngineering.com

RE: Weldability test for early to mid-1920's steel

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  

RE: Weldability test for early to mid-1920's steel

Editorial Correction;

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

Sorry for the slip!

Best regards - Al  

RE: Weldability test for early to mid-1920's steel

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

RE: Weldability test for early to mid-1920's steel

(OP)
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.

www.PeirceEngineering.com

RE: Weldability test for early to mid-1920's steel

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.

RE: Weldability test for early to mid-1920's steel

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

www.PeirceEngineering.com

RE: Weldability test for early to mid-1920's steel

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

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