Steel

 Let us know various terms before we learn about steel preparation.

Alloy - combination of two or more metals and its componeney

Rock - aggregate of minerals

Minerals - A solid substance which is present in nature and can be made of one element or more element

Ore - naturally occuring solid mineral from which a metal can be extracted


Steel preparation are done in two methods

Oxygen process 

In oxygen process the steel is prepared using pressurised oxygen in which carbon rich 

molten pig iron is converted into steel



 Electric arc furnace method 

In electric furnace they use carbon electrodes i.e when the units are melted and converted into high quality steel. These electric arcs formed between a cathode & anode.  Electric current is passed through it which helps in preparation of steel.





Tempering

 Increases strength , hardness and ductility. It is a heating and controlled cooling process.


Annealing 

It is a process of cold working, cutting and forming.

Heating and cooling it very slowly makes the steel soft.


Galvanization 

it is an zinc coating in steel to prevent rusting

hot dipped method immersing metal in the bath of molyen zinc to form thin layer. it increase durability by preventing oxidation. reapeating the process to form yhick coating. corrugation should be moulded before galvanized. The final metal apperas to have a zinc matte finish


Gold dipped method 

A zinc layer is electrically created due to dipped electrodes. This is a less durable method. Hot steel sections are cheaper, easy to make, larger in size and have a  temperature of 1700 degrees Fahrenheit. It is used in rail roads and I beams. Cold steel section has high tolerance, very hard to work with cold steel, it has good surface finish.


Ways to prevent corrosion


Painting

Galvanisation

Chemical treatment


Reaction with fire 

It loses it strength with the increase in temperature. It can result in permanent change in the steel microstructure


Painting

Stainsteel does not require to be painted for protection. But it is not so effective as other processes. It is majorly used as asthetics process


Enamelling

Surface is coated with ceric powder and baked in oven at high temperature. It is also a form of protection process


Physical vapour deposition

The colours obtainable are gold , bronze, rose gold, and burgundy. This process enchances the specific mechnical properties and friction coefficient.


Weathering - The process results change in appearance and texture due to long exposure to atmosphere. Mild steel and low alloy steel are highly susceptible to react with oxygen. This can cause rust in coastal and marine locations

        

Akshay harish.s


        

Comments

Post a Comment

Popular posts from this blog

Steel Erection, Fabrication and Hybrid construction -Blog 16

Image
This blog is about how the steel sections are transported to the site, the issues involved with transportation, erection and fabrication along with the onsite constrains. TRANSPORTATION: The steel sections have to transported from the manufacturing site to the fabrication site and this becomes a tough task due to their size. Often large pieces cannot be transported in a single part, they are split or divided and shipped as two separate pieces or even as one piece to avoid damage or scratches. Temporary connections are made on the pieces to avoid damage and to keep the parts in place during transportation.     These parts are not transported in normal vehicles but require long trail vehicles to fit their length and size which again becomes a difficult task to turn around the corners of the road and at junctions     FABRICATION & ON SITE CONSTRAINS: Fabrication of steel on sites which are along the main road or at the corner site is very hectic as there is very...
Read more

BLOG-16 FABRICATION, ERECTION AND HYBRID STRUCTURES

Image
  FABRICATION: The process of  steel fabrication  involves grinding, welding, cutting, bending, drilling, punching, burning or melting and other general crafting methods using various high-quality tools and CNC equipment. ERECTION LIFTING, POSITIONING AND PLACING OF STEEL MEMBERS IN A STRUCTURE  Once the member(s) are lifted and placed in the required place, with the help of temporary supports and equipment, they are fastened and fixed, depending on the nature of connection.  Erections may be achieved by two techniques such as MEWP(Mobile Elevating Work Platforms) by Mobile crane and Tower cranes. HYBRID STRUCTURES Hybrid structures are structures built with composite materials a combination of different materials with steel. A common  hybrid system  consists of hollow core slabs together with steel or cast-in-situ concrete frames                       EXAMPLE STEEL WITH TIMBER     I...
Read more

STEEL , ALLOYS AND THEIR COMPARISON

Image
BLOG- 8                                     STEEL , ALLOYS AND THEIR COMPARISON                                                               STEEL AND ALLOYS                                               An alloy is a blend consisting of metal and other elements. Alloys are generally made for achieving properties like greater strength or resistance to corrosion. Steel is an alloy of iron. It mainly consists of iron with some small amounts of carbon. Definition ALLOY :      A homogeneous mixture of a metal with other types of elements                       ...
Read more