Duplex steels are formed from a combination of austenitic phases and ferrites, which gives them higher strength and good corrosion resistance compared to austenitic steels. The price charts of stainless and duplex steel is not that different and They are also weldable like austenitic steels. This steel has special applications where strength is required, such as in pressure pipes. By adding nickel (8% to 20%) to iron-chromium alloys, it is possible to produce steels that remain austenitic at room temperature. This steel is corrosion resistant and magnetic when exposed to a magnetic field, but it is not a permanent magnet. 
They are weldable due to their low carbon content. 304 steel is an economical example of this type for general applications. The modified corrosion-resistant version is 316 steel, which is used for industrial use and is the most corrosion-resistant steel in this group. The addition of the letter L to this group of steels indicates improved weldability. Heat resistance can be improved by adding titanium to austenitic stainless steels, such as 321 steel used in the aerospace industry. By adding carbon (up to 2%) to the ferrochrome alloy, its hardness can be increased to become martensitic steel. This steel has a wide range of properties. It is magnetic, although not as corrosion resistant as austenitic and ferritic stainless steel. This type of steel is used in many applications where, in addition to corrosion resistance, high strength, and hardness, and wear resistance are required. Martensitic steel is used to make knives and scissors because of its good wear resistance and high hardness. By adding 12% to 18% chromium, the resistance of this steel can be significantly increased and it can be used to make turbine blades, razor blades, and surgical instruments. 410, 403, and 416 are among the most widely used grades of this type of stainless steel. 416 steel has the best machinability of all steel grades. 410 steel is used to manufacture pump shafts and parts for food processing machinery. 403 steel is also used where the metal is exposed to high temperatures, e.g. in turbines. Ferritic stainless steels are alloys of iron and chromium (more than 17% chromium). The structure of these alloys remains ferritic under normal heat treatment conditions, which is why they are called ferritic steels. This steel has high corrosion resistance but is cheaper than nickel-containing alloys because it does not contain nickel in its composition. Compared to austenitic steels, this type of steel has a more limited field of application because it is not ductile and has poor weldability. Heat treatment cannot be used to harden this type of steel, but cold forming and hammering can help. 
Ferritic stainless steel is widely used in the manufacture of kitchen appliances, and decorative and architectural applications due to its reasonable price. It is also widely used where corrosion resistance, hammerability, ductility, and cost are important, but strength is not so important. Stainless steel is an iron-chromium alloy that contains 10% to 30% chromium and has high corrosion resistance. Although there are many grades of stainless steel, only a few are commonly used in industry. For example, AISI type 304 stainless steel, which uses a combination of chromium, nickel, and low carbon, is very popular in products such as kitchen sinks due to its corrosion resistance, cleanability, and ductility, and AISI type 316 stainless steel contains molybdenum, which is more 304 more resistant to chemicals and is ideal for environments where the product comes into contact with seawater, sulfuric acid or salt water. Stainless steel is an alloy made mainly of iron and carbon. Stainless steel is different in that other alloying elements such as chromium (Cr) and nickel (Ni) are added to create a corrosion-resistant product. When chromium is added to steel, chromium oxide is formed, which works to protect the surface from corrosion by air and moisture, just like ordinary steel. There are more than 100 different grades of stainless steel. Corrosion resistance is the main advantage of stainless steel, but not the only one. Stainless steel includes:
- Resistant to high and low temperatures
- strong and robust
- it has an aesthetic appeal
Environmentally friendly and recyclable In addition to chromium, stainless steel is also made of silicon, nickel, carbon, nitrogen and manganese alloys. For example, nitrogen improves tensile properties such as ductility. Nickel is added to austenitic steels to make them more flexible. 
These alloys are used in varying amounts and compositions to suit specific applications, which is why it is important for stainless steel manufacturers to confirm the percentage of alloy used. Stainless steel is a versatile material. Originally used in service, it quickly found its way into the chemical industry due to its corrosion-resistant properties. Today, corrosion resistance is still very important and there is a growing understanding of the mechanical properties of materials. Stainless steel is available as coil, plate, rod, pipe and wire. Include: kitchen application
- sink
- Knife and fork
- Kitchen equipment
Surgical instruments and medical equipment
- hemostatic agent
- surgical implant
- Temporary crown (dental)
bridge construction
- Monuments and statues
- airport roof
Automotive and aerospace applications
- body
- subway
- plane
kitchen application The most well-known use of stainless steel is in tableware and kitchen utensils. The best type of cutlery is used 304 steel, which contains (18% chromium, 8% nickel). The most demanding industries that use stainless steel are the chemical, oil, and gas industries, creating a huge market for stainless steel tanks, pipes, pumps and valves. First success with 304 stainless steel; storage of dilute nitric acid as it can be used for thinner sections. Several special grades of stainless steel have been produced for higher corrosion resistance over a wide temperature range. Stainless steel and other corrosion-resistant alloys are widely used in the power generation industry to combat corrosion, especially at high temperatures. In particular, nickel alloys are used for high temperature resistance and oxidation resistance in fossil fuel power plants. Nickel alloys and other stainless steels are widely used in flue gas descaling devices. The nuclear power industry uses large amounts of stainless steel, often characterized by low cobalt content, for power generation and radiation control. Steam and gas turbines use stainless steel because of their corrosion and heat resistance. Large amounts of stainless steel are used in food production and storage. The most common stainless steels are 304 and 316. In general, 316 stainless steel is used in higher hardness environments. 
One of the main advantages of stainless steel in this application is that it does not impart any flavor to the food it comes into contact with and it is easy to wash up. Architecture, building, and construction Stainless steel is used in most modern buildings for cladding, roofs, and facades. Airport roofs are often used to build bridges, buildings, and sculptures. Surgical instruments and medical equipment Due to its hygienic quality and ease of cleaning, stainless steel is used as a standard material for most medical equipment, orthopedic beds, and examination equipment. Pharmaceutical companies use stainless steel for pill funnels, plumbing solutions, and more. The automotive industry In car production, they mainly use stainless steel for exhaust systems and catalytic converters, as well as for bodywork. The stainless steel market continues to improve with a greater focus on achieving long-term maintenance costs, reducing environmental impact, and increasing focus on life cycle costs. 
stainless steel price chart
There are some differences between the price chart of stainless steel and carbon steel. Steel is an iron alloy where iron is its basic element and carbon is its main alloying element. The percentage of carbon in different types of steel varies. The maximum carbon content in steel is around 2% by weight. Remember, of course, that steel is not composed entirely of iron and carbon, the simplest types of steel have other alloying elements besides these two elements. Carbon steel and stainless steel differ in certain situations, including:
- Corrosion resistance
- Mechanical behavior
- appearance
- cost
The most obvious difference between carbon steel and stainless steel is corrosion resistance. In general, stainless steel is more resistant to corrosion. Both steels contain iron, which oxidizes and rusts when exposed to air. Chromium added to stainless steel increases the corrosion resistance of this metal compared to carbon steel. Chromium binds to oxygen more easily than iron; by binding chromium to oxygen, a protective layer of chromium oxide is formed that protects the metal from damage and corrosion. Carbon steel generally does not have enough chromium to form a chromium oxide layer; therefore, oxygen has a chance to bond with iron, which can lead to the formation of iron oxide or rust. Therefore, if corrosion resistance is an important factor in your project, stainless steel will be your best choice. 
Mechanical properties: The difference in mechanical properties of carbon steel and stainless steel is not easy to express because each contains different types and grades. Stainless steel has higher formability than carbon steel due to its high nickel content. However, very brittle stainless steel grades, such as martensitic grades, are also found in this group. Stainless steel generally has higher tensile strength than carbon steel due to the presence of alloying elements in the structure. However, if a sufficient amount of carbon (at least 0.30% by weight) is present in carbon steel, this metal will be easier to heat treat than austenitic stainless steel. appearance: While stainless steel and carbon steel can be sanded and polished to a bright and shiny appearance, carbon steel must be painted shortly after the metal polishing process. Without this action, the carbon steel will begin to tarnish and eventually rust; moreover, if the stainless steel is scratched, it will still retain its luster in the scratched area, but carbon steel must be repainted under the same conditions, otherwise, it will corrode. cost: Another thing that makes the difference between carbon steel and stainless steel is the cost. While prices vary for different grades, stainless steel is generally more expensive than carbon steel. Due to the addition of alloying elements such as chromium, nickel, and manganese to stainless steel. All these added elements increase the cost compared to carbon steel. 
Types of pig iron There are different types of pig iron: cast iron When molten pig iron is cooled rapidly, its carbon does not turn into graphite. Therefore, brightly colored iron (which turns silvery white) is called pig iron and is used for steelmaking. In white pig iron, the silicon content is low, the material is hard and tough. gray pig iron When molten pig iron is cooled slowly, its carbon turns to graphite. As a result, the iron becomes darker in color and is called gray pig iron, which is used for cast iron. The silicon content of gray cast iron is high and it is soft white, so its cross-section has coarse and gray grains. half gray cast iron This pig iron sits between gray and white iron and is used to make steel and cast iron. What is galvanized steel? Galvanized steel is a type of steel coated with a zinc layer that prevents the steel from rusting. This layer is usually very thin, measured in thousandths of an inch or micron. To make galvanized steel, a zinc coating is usually added after the steel sheet has been melted, refined, and shaped. Sometimes this is even done after processes such as bending or welding galvanized steel. Stainless steel resists corrosion due to the presence of chromium (and sometimes other added elements). Carbon steel corrosion occurs when the iron in the steel has the opportunity to combine with oxygen in the environment. 
The chromium in stainless steel prevents it from corroding when it combines with oxygen and forms an extensive layer of chromium oxide. As long as there is enough chromium in the steel, the formed chromium oxide layer prevents the formation of iron oxide (also known as rust). The amount of chromium and other alloying elements required determines the different grades of stainless steel. How does galvanized steel resist corrosion? Galvanized steel resists corrosion due to the zinc coating on carbon steel. Zinc plating serves two purposes:
- By preventing contact of oxygen with the steel, the possibility of metal corrosion is reduced.
- Even if the zinc layer is deformed and a small amount of iron is exposed to the surrounding air, the remaining zinc is far more active than steel. This allows zinc to attack oxygen molecules faster than iron and prevents rust.
Stainless steel has the following properties: Stainless steel is generally more expensive than galvanized steel. This steel generally has higher corrosion resistance than galvanized steel. If stainless steel is scratched, it can still retain its corrosion resistance around the damaged area, but if the zinc layer on galvanized steel is damaged, the carbon layer underneath is still fragile. As large sheets of stainless steel are dipped in zinc and then cut, the cutting edges are exposed to oxygen, increasing the risk of rust. Aesthetically, stainless steel has a more desirable appearance than gray galvanized steel due to its shine and silver color.