What is Steel?

  What is Steel?The alloy, which is based on iron and has less than 2% carbon, is called steel or steel. Depending on the type and amount of other elements in it, mechanical properties such as hardness and plasticity are determined.

What is carbon steel and alloy steel?

Steels are classified into two simple carbon and alloy categories. In plain carbon steel, there is no element other than carbon and some common elements (such as silicon, manganese, sulfur and phosphorus). The simple carbon steel classification is as follows.

Simple carbon steel cuttingCarbon percentageUses
SoftLess than 1.5%Nails, rivets, seam pipes
Low carbon۱۵۰٫ to ۰۰۳Beams, round bars, gears
With medium carbon۳۰٫ to ۰۰۶Shaft, crankshaft, spring
High carbon۶ ٫ ۶ upSaws, wrenches, drills, screwdrivers

Adding some elements to the iron produces alloys that have excellent properties. For example, by adding chromium to iron, stainless steel or stainless steel is obtained which is highly resistant to various corrosions.

What Makes Stainless Steel Stainless?

Steel is corrosion-resistant when it contains at least 1.5% chromium. Chromium is formed by combining with oxygen to form chromium oxide, which forms a layer on stainless steel. This layer is not visible but causes the connection between the air and the metal to disappear and the steel to remain healthy. Higher amounts of chromium, as well as some other elements in the nickel-molybdenum-like alloy, reinforce this layer and increase the corrosion resistance.

What is the difference between steel 1 and 2 ?

Steel 2 contains 5% chromium and 2% nickel, while steel 2 contains 5% chromium, 2% nickel and 2% molybdenum. Molybdenum is added to help resist corrosion caused by chloride (such as seawater).

Do stainless steel attract magnets?

Series 7 nickel-plated stainless steels are not absorbed by the magnet, whereas the nickel-series Series 2 is chromium-free.

What is the letter L after the name of the stainless steel (like ۳۱۶L)?

The letter L denotes the word low carbon, indicating that the carbon content of the alloy has been reduced to less than 0.5%. This low carbon makes the protective oxide layer still present on the surface after welding.

Can stainless steel be recyclable?

Stainless steel is 2% recyclable. The scrap steel is melted and molded again. Between 2 and 4 percent of stainless steel production is done through waste recycling.

Can stainless steel work at high and low temperatures?

Yes, stainless steel has good resistance to extremely high temperatures (up to 1000 degrees Celsius) and very low temperatures (up to negative 2 degrees Celsius).

Who did the naming of the steel (1, 2, …)?

The American Iron and Steel Society (AISI) for the first time categorized and named stainless steels and provided physical and chemical specifications as well as manufacturing instructions.

What kind of steel is CK45 ?

A simple medium carbon steel type (about 2.5%) that is sometimes used for pump shaft construction because of its low price. It is not resistant to rust and corrosion due to its low chromium content.

What is Duplex Steel?

This type of steel has between 5% and 5% chromium and up to 5% molybdenum and has a very high corrosion resistance and is therefore the best option for making corrosion-proof seawater components.

What is a stainless steel?It is a type of alloy steel with a higher percentage of nickel and chromium than other constituents. Generally speaking, if the chromium content of steel is more than 1.5%, it is called stainless steel. This amount of chromium causes a thin layer of corrosion to form during the corrosion, preventing further corrosion and practically repairing the corrosion. Meanwhile, its carbon content is less than 1.5%.

Types of stainless steel grids

Series 2 or stainless steel (non-magnetic): Iron alloy, chromium, nickel with carbon less than 0.5%. Series 2 or stainless steel (magnetic): Iron alloy, chromium with carbon less than 0.5%.

Series 2 and its applications

The most common grade is stainless steel, which is a classic 1/4. It is the most common grade after grade 2 and is used in the food and surgical industries, in addition to preventing molybdenum alloy. It is also used in the marine industry because of its high resistance to chlorine compared to Grade 4.

Series 2 and its applications

است It is wear-resistant but has little resistance to corrosion. کار Cutlery grade has good polishing performance ۴۳۰ Decoration grade is used for example in interior decoration of cars. Has good plasticity at low temperature and is corrosion resistant.

Properties of stainless steel

  • Corrosion resistant
  • Attractive appearance
  • Heat resistance
  • Fully recyclable
  • Long and useful life compared to payment

Stainless steel is an alloy of steel consisting of 0.5% or more chromium and more than 5% iron. By adding more percent chromium and other alloys like it improves .


Golden doors and fences are not painted and using this advanced method, titanium ions are applied to the steel and change its color. It is noteworthy that unlike similar examples, other lifelong colors do not change and do not ring, due to the use of this new technology .

What is stainless steel and who is its inventor?

Stainless steel is a group of alloys with an iron base that contains at least 2 % chromium (Cr) . Chromium is an essential element that forms a stainless steel film on the surface of the chromium oxide . When the stainless steel is cut or scratched, the chromium on the surface is rapidly oxidized and the damaged oxide film is repaired. Because of this property it is self-healing which is called stainless steel . The first stainless steel alloy, martensitic   Fe-Cr-C was developed by English scientist Harry Brearley at 6 . The first commercial stainless steel casting was produced in Sheffield, England, in the year 6, and the American patent for the invention was granted to Mr. Harry Berley in the year 2 .

Does stainless steel rust?

In fact, the fact that stainless steel does not rust is a misconception. This inaccurate understanding in some cases leads to disputes and even prosecutions between employers and contractors. Stainless steels will remain stainless only under certain conditions, such as unpolluted environments, and fresh water or seawater (current). In wet marine air or in stagnant (stagnant) water, type 2 stainless steel rusts, and often locally develops cavity corrosion. In general, the nature of the environment and the chemical composition of steel both play a decisive role in the formation of corrosion and corrosion of stainless steel .

What is the reason for chrome layer removal during heat treatment?

In heat treatment or welding, the temperature of the stainless steel reaches to about -5 ° C. Chromium and carbon interact with each other, producing chromium carbide, which precipitates along the grain boundary. for this

The reason for the chromium in the surrounding area is draining. The boundary region where chromium is depleted (poorer than chromium) is less resistant to corrosion than other healthy areas of the metal surface where chromium is not depleted .

The stainless steel in which the crystal structure of the work must be chrome-plated   (Sensitized) . ” Alloyed steels are more susceptible to cross-corrosion or weld corrosion .

Catch steel   And   do not get

Call it stainless steel which is adsorbed by magnets and don’t say stainless steel that is not absorbed by magnets . Series 2 stainless steels (such as 1 and 2) have chromium, leading to stainless steel. And while the Series 6 steels only have chrome that retains the magnetic properties of stainless steel.

One of the ways to distinguish stainless steel from carbon steel is that if the magnet is not stuck it is definitely stainless steel but if the magnet sticks to it there is still no reason to distinguish stainless steel from carbon steel. ..

Therefore, to choose a suitable stainless steel, many considerations, such as the grade of steel, the level of steel, its use, and the magnetic properties of the steel.

History of stainless steel

In metal science, stainless steel is known as stainless steel or stainless steel, which is derived from the French word “inoxydable” meaning “stainless”.

Stainless steel does not rust easily. There is rust or water rust in ordinary steel but despite its stainless steel name it is not completely rust resistant, it is suitable for low oxygen locations, as well as other stainless steel alloys. There is a corrosion-resistant steel or CRES. When there were no details of the type and grade of steel. This type of steel was used in the aviation industry. There are now different grades of steel with a beautiful view to use in the environment based on consumer needs. Stainless steel, or stainless steel, is used in places where we need every advantage of high strength and corrosion resistance.

Stainless steel comes with carbon steel and varying amounts of chromium. Carbon in the steel, if unprotected, can easily rust when exposed to oxygen and moisture. Corrosion accelerates corrosion and corrosion, and in the long run causes corrosion and corrosion and corrosion of the metal. The stainless steel has a sufficient amount of cream to form an inactive layer of cream that prevents the surface from corroding and penetrating the metal surface.


It was the first time an ad about the discovery of Stainless steel had been published in The New York Times in the past year. There have been several types of rust-resistant iron alloys since ancient times. A famous example of this type is the Pillar of Delhi alloy. This stainless steel was made by Kumara Gupta in the year 9, when the stainless steel did not owe its stainless steel to chromium. The metal obtained its stainless steel from high phosphorus conditions. Local weathering caused a layer of corrosion-resistant iron oxide and phosphate. The first alloy of iron and chromium was introduced by French metallurgist Pierre Berthier in 5, which was resistant to some acids and was suitable for spoon and fork making. Metallologists have been able to produce new stainless steels with a combination of low carbon and high chromium since the 5th century, and high chromium alloys were extremely fragile.
In the late 1980s the German “Hans Goldschmidt” made some progress in the process of producing chromium and carbon. Between the years 1 and 2, a number of researchers, especially the French “Leon Guillet” made alloys, which we now know as “stainless steel”.
In the year 9 Friedrich Krupp Germaniawerft built a 4-ton ship with steel chrome and nickel body in Germany. In year 3 Philip Monnartz wrote a report on the relationship between nickel content and corrosion resistance. On October 2, Crop engineers Benno Strauss and Eduard Maurer stainless steel named ThyssenKrupp Nirosta.
Similar developments were taking place in the United States at the same time. In which ChrisTiyan Dantsizen and Frederick Becket discovered ferritic stainless steel. In the 5th year, Elwood Haynes filed for a United States patent on a type of martensitic stainless steel, which was not granted until year 6.
Also in the 1980s, Harry Brearley of Brownfield Research Laboratory in Sheffield, England, discovered martensitic stainless steel while researching a corrosion resistant steel pipe. The discovery was published in the New York Times newspaper two years later in January; The metal was later marketed under the brand name ‘Staybrite’ by Firth Vickers’ Firth Vickers and was used for the new entrance shed at the London Hotel in year 6. Brearley filed for steel during the year that he found Haynes had filed a similar patent in the US Patent. Brearley and Haynes merged their funds together with a group of investors, Stainless Steel, which had its headquarters in Pittsburgh, Pennsylvania.
Initially stainless steel was sold in the United States under various brands such as Allegheny metal and Nirosta steel. Even in the metallurgical industry there was no single name for it. In year 3, a business magazine named it “unstainable steel”. In the year before the Great Depression, statistics showed that more than 1.5 tonnes of stainless steel were manufactured and sold in the United States. Stainless steel is one of the most widely used engineering materials due to its excellent corrosion resistance. This resistance is due to the high amount of chromium in them. A low chromium content, such as 1%, increases the corrosion resistance of iron slightly, but at least 1Cr% is required to achieve stainless steel . According to classical theories, chromium forms a surface oxide layer that layers

Protects the underside from corrosion, reinforces the iron surface. To create this protective layer, the surface of the stainless steel must be in contact with oxidizing agents.

Stainless steel application in everyday life


Stainless steel is actually the most important alloy of iron, and steel is widely used in today’s industry. Almost most industries use this alloy. In fact, they keep the quality of their products high.

Stainless steel is used in the automotive industry, making beautiful handles for store and apartment doors, kitchen appliances, elevators and more. In the meantime, stainless steel is widely used in the kitchen.

Stainless steel, or stainless steel, has a very high resistance that is not easily combined with air oxygen and therefore does not corrode in this alloy.

This has made it a popular fan in humid and humid areas. In this post we will briefly mention steel consumption.

Stainless steel used in furniture making


The use of stainless steel in the furniture industry is very important. It is important in this industry that the materials used in the manufacture of furniture are of high strength. In some areas wood cannot be used in the industry, so steel is very important.

Also, stainless steel does not corrode and does not require staining.

The use of stainless steel in power generation


This refractory alloy is used in most parts of power turbines. Because it is very durable, it is used in the manufacture of bolts, gears and other parts. The use of stainless steel in the power generation industry is so widespread that we have done just that.

Using stainless steel in the kitchen


Today, steel is the most widely used industry. Most kitchen utensils are made from steel. All kinds of spoons, forks, pots and pots are of the same style.

In addition, the food, dairy and confectionery industries use this type of steel.

The use of stainless steel in the manufacture of hospital equipment


Equipment and tools made with this type of steel are easily cleaned and sterilized and will never be damaged or damaged. The most important use of this alloy in the manufacture of hospital equipment is the manufacture of implants because the stainless steel alloy is well adapted to the human body and implantation in the mouth is not adverse.

Use of stainless steel in agricultural tools


Because fertilizers and fertilizers are used repeatedly on farms, a corrosive environment is provided for the farm equipment to be eaten, and agricultural machinery and equipment are eaten and damaged.

Therefore, this alloy is used and the tools of this industry are stainless. At first glance it may be thought that the cost of purchasing these devices is very high, but for many years the devices are insured and do no harm.

Thanks – Abraham Zarei