Steels_ Metallurgy and Applications, Third Edition

Low-carbon strip steels 95

if special capping pieces are inserted to melt the coating. 149 However, mechan-

ical joining techniques have been developed specifically for coated steels and

adhesives are also available that are suitable for particular types of coating.

Steel prices

The basis prices of standard hot-rolled and cold-reduced strip grades are shown

in Figure 1.99. These prices were effective in February 1997 and it must be

borne in mind that steel prices are adjusted periodically. This figure shows that

a substantial differentiation is made between the hot-roUed and cold-reduced

conditions, reflecting the additional processing costs associated with the latter.

However, the cost differential within these two conditions with respect to the

various formability criteria is relatively small.

Figure 1.99 also includes the basis prices for zinc-coated steels. This indicates

that electro-galvanized strip costs about s more than uncoated, cold-

reduced steel. However, the cost differential is substantially more in the case

of hot dip galvanized strip, which has a heavier zinc coating than the electro-

galvanized product.

600

550

500

(^0) C
L 450
400
350
z.
rolled
uncoated
Co'd-
reduced
uncoated

Electro-

zinc

coated (1)

r

Hot

dip

galvanized (2)

Figure 1.99 Basic prices of strip mill products: (1)Zinc coating 2.5 pm both sides;
(2) Zinc coating 275 g/m 2, including both sides: as of February 1997