In his suitable vision of growth and development, the man has been using “Stainless Steel” since the beginning of twentieth century. We have celebrated the “Diamond Jubilee” of this steel because of its “Stain-less” nature. Its unfading attractive appearance makes its name scintillating in the world till today. Higher corrosion resistance, cryogenic toughness, strength and hardness are responsible for keeping this steel’s surface stain free. Stainless steel not only stand firm in rain but also gives you minimum maintenance pain. Its omnipotent nature is due to the excellent physical and chemical properties, it exhibits under a wide range of temperature and pressure. During its tenure, stainless steel have made its presence everywhere, from a small pin to an aeroplane, all have stainless steel embedded in them in one form or another.
Stainless Steels have been classified into five categories based on their different composition and manufacturing process involved. These are Austenitic, Martensitic, Ferritic, Duplex and Precipitation Hardened respectively. As the composition differs, same is true for application.
Austenitic Stainless Steel found use in different sectors depending upon the type of grade as follows:
- SS 304 / 304 L – Tanks, Storage vessels, Sinks, Cutlery, Architecture.
- SS 309/ 310- Furnace, Kiln, Catalytic convertors.
- SS 318, 316 L – Chemical Storage Tanks, Pressure Vessels and Piping.
- SS 321, 316 Ti – After burners, Super Heaters, Compensators, Expansion Bellows.
- SS 200 series – Dishwashers, Washing Machines, Cutlery, Cookware, Food beverage equipment.
Martensitic Stainless Steels are used in making surgical and dental instruments, wire, screws, razor strips, springs, blades, cutting tools, fasteners, gears, gauge blocks, moulds and dies, ball bearings and races, aerospace, cutlery, defence, power hand tools, valve seats, chisels, bushings, shafts and sporting industry etc.
Ferritic Stainless Steels can also be used as an alternative to austenitic stainless steel in the manufacturing of thin film products like exhaust tubing and systems, washing machine drums, containers, buses, train compartments, LCD monitor displays, microwave and solar water heaters.
Duplex Stainless Steels are used in products which have high endurance in hot working conditions. Some of the applications are as follows :
- Pressure vessels, heat exchangers.
- Marine and high chloride conditions.
- Paper and pulp industry-digestors, bleaching equipment and stock handling systems.
- Food processing equipment.
- Biofuel plants.
Last but not the least, Precipitate Hardened Stainless Steels are used specifically in aerospace applications, pump shafts, oil and gas industry and nuclear reactor components.
After having a broader technical outlook on the application of Stainless steel, there is a need to have an insight as per commercial usage perspective. On the basis of market segregation, stainless steel is prevalent in the following areas:
- Medical Use: – Stainless steel is being used for the manufacturing of surgical, knives, clamps, spatulas blades, needle holders, forceps etc. Stainless steel is not only used in pacemaker to beat your heart normal but also, it is used in artificial vales of heart to help pump the blood through it properly. Moreover, many small parts of hospital machineries like EKG, ECG, and stretchers are made out of stainless steel.
- Infrastructure: – The extreme corrosion resistant nature of stainless steel makes it fit for use in bridges construction, railways, marine and aviation industry. There all are the lifelines of Indian Economy which get strengthened because of good quality stainless steel that do not get corroded easily under the action of wind and water. Architectural applications such as cladding and roofing, doors and window find use of stainless steel.
- Machinery: – The high conductivity and cryogenic properties of stainless steel have gathered the attention of researchers and scientists. They recommend use of stainless steel in making of turbine heat exchanges chemical tanks, ovens, desalination plants, food pickling plants, chemical and petrochemical plants. Various industries like marine (off-shore oil and gas installations), paper and pulp have several mechanical components made out of stainless steel.
- Defence and Domestic : – Stainless Steel is being need in defence sector since the world war II . Springs in artillery guns, fasteners in tanks, missiles are used due to high tensile strength and light weight nature. Fuel lines carrying vehicle exhausts, cooking utensils and kitchen sinks are common products composed of stainless steel which are being used by us in day to day life. . Only domestic use of stainless steel accounts for three- fourth of its total consumption.
- In a nutshell we can conclude that stainless steel due to its diversified usage and per capita consumption is going to become the “Metal of Future”. Though it seems to experts that stainless steel have attained maturity, but there lies a vast scope to increase its demand and production because of its iconic applications. This establishes the fact that stainless steel will bloom out with flourishing colours in the twenty-first century too as per past dignity and legacy.