BLOG 5 - CORROSION PREVENTION OF STEEL

      PREVENTING CORROSION      


            In today's session, we discussed how to prevent steel from corrosion.

Here are some examples to prevent steel from corrosion.
  • Cold hardening
  • Galvanization
  • Quenching
  • Tempering 
  • Annealing
            As discussed today in class there are two ways to shape the steel which is hot rolled and cold rolled steel.

(i) Hot rolled steel is where it involves rolling the steel at high temperature and it is rolled out of casting area to a specific thickness.
(ii) Cold-rolled steel is the hot rolling method carried out by further process where the material is cooled, followed by the annealing process.

            Quenching is the process where it heats the steel and quickly cools it in water, oil, air which creates a thin layer that is strong and brittle.
            Tempering increases the strength, hardness, and ductility which is controlled by the cooling process. 
            Annealing( cutting and forming) is the process where it increases the ductility and reduces the hardness of the material. 
            Coming to the galvanization process, it is the process of applying zinc coating to prevent rusting.
  • The hot-dipped method is the process of coating the base metal by dipping into a bath containing zinc coating metal which means the base metal should have a high melting point compared to zinc coating metal which has a low melting point. 
            The hot steel section is cheaper, and it is easy to make compared to the cold steel section. The hot rolled steel sections are used in construction to make I-beams and railroads. 
            In the cold-rolled steel section, it is processed into cold reduction mills where the steel section is cooled.

There are many ways to prevent corrosion. Using paints, they can provide corrosion. Zinc coatings can provide corrosion protection to steel structures exposed to the environment. 

            They can also be prevented by the galvanization process and by undergoing chemical treatment.
            Next, we were discussing on how steel reacts with fire.
            Steel material is non-combustible but will lose its strength and it becomes ductile at high temperature.
            Ways to prevent steel from the fire are as follows:-
They can undergo chemical treatment and it can be enclosed with gypsum layers.

 

Next moving on to the stainless steel, the stainless steel is more expensive than carbon steel. 
            There are many types of surface treatments on stainless steel. 
Some of these are electro-polishing, electrolytic coloring, burnishing, acid etching, painting, and enameling.

  • Electro-polishing is an electrochemical process that removes the surface of the metal and reduces the surface roughness.  
  • Enameling is the process where the stainless steel is coated with a mixture of ceramic powder and baked it to an oven at high temperatures.

              Stainless steel is highly resistant to atmospheric corrosion, and it retains its original state.
To be continued....

Anjanalakshmi M


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