|
| |
STAINLESS STEEL
Colour - silvery grey
Specific Gravity -
Invented - 1913
Invented by - Harry Brearly of Sheffield, England
Strength - strong
Corrosion Resistance - resists rusting because of the chromium element
Tensile Strength -
Hardness -
Melting Point -
Stainless Steel
Stainless steel is actually an alloy rather than a metallic element of itself. One of the most common alloys is 18/10 stainless steel ( having 18% chromium 10% nickel and 72% iron ). Chromium and nickel give the stainless it's rust resisting properties.
Invention
While experimenting with an alloy of steel suitable for gun barrels in 1913, an Englishman, Harry Brearley of Sheffield cast aside an unsuccessful attempt containing 14% chromium. Some months later he noticed that this sample remained bright while most other samples had rusted. From this discovery the stainless steels of today have been developed.
History
Stainless steel has increased dramatically in it's use since it's invention in 1913 to become part of everyday life.
Uses
Stainless steel is commonly used for household cutlery and kitchen sinks. Jaguar and Rolls-Royce use stainless steel for external bright trims. The Sydney Opera House even incorporates some stainless steel.
Working Properties for Craftspeople
Stainless is a fairly hard metal, making working with it slow by comparison to other metals ( such as silver ). With some difficulty stainless may be soldered, however generally mechanical methods are employed ( like rivets ).
Types of stainless steel
There are three main types of stainless steel - ferritic, martensitic and austenitic. The ferritic steels are magnetic and have a low carbon content and contain chromium as the main element, typically at the 13 % and 17 % levels. The martensitic steels are magnetic containing typically 12% chromium and a moderate carbon content; they are hardenable by quenching and tempering like plain carbon steels and find their main application in cutlery manufacture, aerospace and general engineering. The austenitic steels are non-magnetic and in addition to chromium, typically at the 18 % level, they contain nickel which increases their corrosion resistance. They are the most widely used group of stainless steels. Other grades of stainless steel include precipitation hardening, duplex and highly alloyed grades.
Melting temperatures of metals
Metal Melting Point (Deg F)
mild steel 2730
wrought iron 2700-2900
stainless steel 2600
hard steel 2555
cast iron 2060-2200
copper 1985
red brass 1832
silver 1763
yellow brass 1706
aluminum alloy 865-1240
magnesium alloy 660-1200
lead 621
babbit 480
| |
|
