what is the difference between type -a and type -b iron > The chemical compostion is given here under and also guide us the effect of Ni;Cr;Mo in the iron; name and use of these two types of iron Type a Type b %C :3.15 2.65 %Mn:0.41 0.52 %Si:1.72 1.60 %S :0.090 0.082 %P: 0.215 0.204 %Ni: 0.40 Traces %Cr : 0.49 Traces %Mo : Traces Traces