STEEL- Physical / Mechanical / Chemical

Properties

Submitted By – Harpreet KaurCUN120301034B. Arch Semester 3 B1

Introduction•Steel is an alloy of iron and carbon.•It is one of the most common materials in the

world.•It is a major component in buildings,

infrastructure, tools, ships, automobiles, machines, appliances, and weapons.

•Types of Steels - Carbon Steels Alloy Steels Stainless Steels Tool Steels

Physical Properties•The properties that need to be considered by

designers when specifying steel construction products are:

•Strength•Toughness•Ductility•Weld ability•Durability•Low weight

Chemical Properties•The difference between a physical and

chemical property is straightforward until the phase of the material is considered. The main properties are -

•Phase Transformation Temperatures•Density•Specific Gravity•Thermal Conductivity•Linear Coefficient of Thermal Expansion•Electrical Conductivity and Resistivity•Magnetic Permeability

Mehcanical Properties•The mechanical properties of a material are

those properties that involve a reaction to an applied load.  The mechanical properties of metals determine the range of usefulness of a material and establish the service life that can be expected. 

•Mechanical properties are also used to help classify and identify material. 

•The mechanical properties of a material are not constants and often change as a function of temperature, rate of loading, and other conditions.

Notch-toughness

•There is always a possibility of microscopic cracks in a material or the material may develop such cracks as a result of several cycles of loading. Such cracks may grow rapidly without detection and lead to sudden collapse of the structure. To ensure that this does not happen, materials in which the cracks grow slowly are preferred. Such steels are known as notch-tough steels and the amount of energy they absorb is measured by impacting a notched specimen with a heavy pendulum as in Izod or Charpy tests.

•If its a RC frame building (Reinforced concrete) then the steel would be in the form of steel bars ranging in diameter from 8mm to 50mm or mesh depending on the calculations made by architects. These bars would be tied together with mild or stainless steel tying wire to form cages which would then be covered with concrete which form walls, columns and floors.

•Steel is also used in the foundations of buildings. This can be from small beams in houses or in the form of concrete piles which are basicly long holes drilled deep into the ground and filled with a steel cage and concrete.

•Other than this the steel could be in the form of RSJs rolled steel joists or steel girders. This is used to build a frame from which floor slabs are suspended.