Metal

Property

Stainless Steel

Constituents

The quality of stainless steel is imparted to steels by the presence of at least 12% of chromium in the steel. Oxidation and/or corrosion produce a dense adherent oxide film which acts as a barrier to further corrosion.

Added Elements

Nickel and manganese are important added elements that produce special characteristics such as strength, toughness, and ease of fabrication in stainless steels. Columbium (niobium), molybdenum, phosphorus, selenium, silicon, sulphur, titanium, and zirconium are also used to give special characteristics. [17]

Material Properties

Source: Stacey, Michael; Component Design; Architectural Press, Oxford, 2001

Modulus Elasticity

Fire and Heat Resistance

Special high chromium and nickel-alloyed grades resist scaling and retain strength at high temperatures.

Corrosion Resistance

Lower alloyed grades resist corrosion in atmospheric and pure water environments, while high-alloyed grades can resist corrosion in most acids, alkaline solutions, and chlorine bearing environments, properties which are utilized in process plants.

Impact Resistance

The austenitic microstructure of the 300 series provides high toughness, from elevated temperatures to far below freezing, making these steels particularly suited to cryogenic applications.

Brass

Brass tapware/ mixer can be either brass finish or, the most popular one, chrome finish.

Chrome plate is valued for its decorative appearance and is also widely used in automotive, office furniture, and kitchen appliances. It produces the hardest of all electroplated coatings, so it’s widely used for parts requiring wear resistance.

Brasses are alloys of copper and zinc (typically around 65% Cu and 35% Zn), and may contain small amounts of other alloying elements. Most are available in a range of forms and can be fabricated by casting, forging, stamping, rolling, extrusion and machining.

They fall into two classes, the alpha alloys with less than 37% zinc which are ductile and can be cold worked and the alpha/beta or duplex alloys which are harder and stronger with limited cold ductility.

Lead can be added as an alloying element resulting in a brass that can be rapidly machined and produces minimal tool wear. Additions of aluminium, iron and manganese to brass improve strength, whilst silicon additions improve wear resistance.

As its application in sanitary fitting material, this particular alloy contains a small addition of arsenic and is specially heat treated so that the composition is homogeneous as water in some countries will attack zinc rich areas of the metal.

Properties

Nickel

One of the main purpose of nickel is as plating metal for steel, and as various applications requiring high temperature and corrosion resistance.

Properties

Nickel increases the elastic limit, hardness and tensile strength of steel, with no loss of ductility. A 3.5% nickel-steel with low carbon content, will have tensile properties corresponding to those of high carbon content steel, but without its brittleness. It is important property that nickel resists to fatigue. A 3.5% nickel-steel is about 6 times more resistance to impact and increases shearing strength. [19]