Steels_ Metallurgy and Applications, Third Edition

Low-carbon strip steels 97

Table 1.12
........... ~ ,
Temper Euronorm/ISO
number temper
designation
, _ ,
T1 T50

Tinplate-single-reduced tempers

,, .............

Typical application

T2 T52

T3 T57

T4 T61

T5 T65

Mainly used for components which make

the maximum demand on the formability of

the steel base, e.g. deep-drawn containers,

bakeware, puddings basins, oil filter bodies

Typically used for forming operations

which are less severe than above, e.g.

shaUow-drawn bakeware, rectangular caps,

cushion rings for paint cans

Used for a wide range of applications where

moderate formability is required, e.g.

shaUow-drawn components, can bodies

Typically used for ends, bodies, stampings

where a stiffer and stronger product is

required

This is the strongest product available in the

conventional temper range and is typically

utilized for stiff ends and bodies

After British Steel Tinplate-Product Range

Table 1.13 Tinplate - double-reduced tempers
.......................
Designation Target proof
stress (0.02%
New Previous non.proportional
elongation) longitudinal
MPa

Target ~pical

hardness applications

FIR 30TM

550 73 Round can bodies

and can ends

620 76 Round can bodies

and can ends

660 77 Beer and carbonated

beverage can ends

.....

DR550 DR8

DR620 DR9

DR660 DR9M

electro-deposition of tin now accounts for the bulk of tinplate production. Prior
to plating, the strip is thoroughly cleaned in electrolytic pickling and decreasing
units, followed by washing. The Ferrostan process uses a bath of acid stannous
sulphate and tin with a purity of not less than 99.85%. After plating, the coating is
flow-melted by resistance heating to a temperature above the melting point of tin
(232~ e.g. 260-270~ followed by water quenching. This treatment produces
a reflective surface and also results in the formation of an iron-tin compound
(FeSn2) which plays an important role in the corrosion resistance and soldering