Subject: What metal is the core of rods used for electric arc welding?

 I need information for a chemistry project. MAny products we use are 
welded by electric arc welding.  Welding rods normally have a metal core 
and an outer coating.  What metal is the core composed of?  What is the 
fuction of the core?  Does it react chemically with the metals to be 
welded?  What chemicals are used to coat welding rods?  What is their 
function?  What chemical reactions are they involved in?
              Thank You

Re: What metal is the core of rods used for electric arc welding?