Question

suggest an explanation following- The Cr and Ni content of stainless steels used to make knife blades is different from that used in the manufacture of spoons.

Answer 1

Hardenable martensitic types of stainless steel, like the ferritics, contain only chromium, but with additional carbon. This enables them to respond to hardening heat treatments and so they can be used for knife blades.

The austenitic and ferritic '18/8', '18/10' and '18/0' stainless steels cannot be hardened by heat treatment and so can only be used for knife handles, forks and spoons.

'18/8' is probably the most commonly used stainless steel and contains 18% chromium and 8% nickel.

'18/10' is a designation used on some cutlery and holloware as an alternative to '18/8'. This designation is claimed to indicate a better quality steel than '18/8', and is essentially the same as the '304 (1.4301) grade . In practice the "10" does not indicate an actual higher Ni content and is purely a marketing

'18/0' is a 'ferritic' stainless steel type, which is attracted by a magnet (like pure iron). This steel is known as '430' in the AISI system or 1.4016 in the European standard.
It is used where corrosion resistance is not too demanding as an alternative to the '18/8' 304 type. The chromium content is optimistically said to be 18% but is nearer 17%.