09-16-2012, 06:18 AM
Hello All,
As most of you know I did my apprenticeship and later trained to be an engineer and worked as a plant metallurgist in a Steelmaking plant, specifically a Rod and Bar producing integrated steelworks.
As a result I helped make a whole lotta Re-Bar, truth is Re-Bar isn't a standard thing across the world it is often made using varying grades of steel, a kind of we've got some of this or that, that is out of spec but will still be OK for Re-Bar as it meets the minimum 250MPa and elongation spec, and then there is the "Good Stuff" Temp Core, which has a hardish skin having been quenched in water/glycol coolant for just a few seconds while the centre or core is left very hot in order to self temper, this gives a stronger Re-Bar that you need less of to do the same job, Temp core is made only from very specific grades of steel and is damaged by welding or hot bending so if being used as Re-Bar these processes should not be used.
BUT, if you want to make anything else out of it weld to your hearts content, there is no problem at all and 90% of it is just good Ole fashioned mild steel, it needs no special care, and contrary to many of the urban myths it isn't a special grade that is corrosion resistant either, it is prevented from rusting only by the strong alkali nature of the cement that encases it, nor is it specifically designed to resist cold temperature embrittlement, it just doesn't get cold enough inside the concrete jacket, and the reason that many folks think it can't be welded is that most building standards say it should only be tied with wire, but this is only to prevent pure tensile loads being put through joined pieces in pretensioned bridge and girder castings, 90% of box grid reinforcing cages are factory welded so the steel itself is weldable.
I hope this helps,
Rick
As most of you know I did my apprenticeship and later trained to be an engineer and worked as a plant metallurgist in a Steelmaking plant, specifically a Rod and Bar producing integrated steelworks.
As a result I helped make a whole lotta Re-Bar, truth is Re-Bar isn't a standard thing across the world it is often made using varying grades of steel, a kind of we've got some of this or that, that is out of spec but will still be OK for Re-Bar as it meets the minimum 250MPa and elongation spec, and then there is the "Good Stuff" Temp Core, which has a hardish skin having been quenched in water/glycol coolant for just a few seconds while the centre or core is left very hot in order to self temper, this gives a stronger Re-Bar that you need less of to do the same job, Temp core is made only from very specific grades of steel and is damaged by welding or hot bending so if being used as Re-Bar these processes should not be used.
BUT, if you want to make anything else out of it weld to your hearts content, there is no problem at all and 90% of it is just good Ole fashioned mild steel, it needs no special care, and contrary to many of the urban myths it isn't a special grade that is corrosion resistant either, it is prevented from rusting only by the strong alkali nature of the cement that encases it, nor is it specifically designed to resist cold temperature embrittlement, it just doesn't get cold enough inside the concrete jacket, and the reason that many folks think it can't be welded is that most building standards say it should only be tied with wire, but this is only to prevent pure tensile loads being put through joined pieces in pretensioned bridge and girder castings, 90% of box grid reinforcing cages are factory welded so the steel itself is weldable.
I hope this helps,
Rick
Whatever it is, do it today, Tomorrow may not be an option and regret outlasts fatigue.