A.≤0.05%(wt) B.≤0.1%(wt) C.≯0.1%(wt) D.≯0.15%(wt)
A.≤2%(wt) B.≤0.5%(wt) C.≯0.74%(wt) D.≯1.5%(wt)
A.≤300ppm(V) B.≤400ppm(V) C.≤500ppm(V) D.≤600ppm(V)