Four Important Things You Should Know About Duplex Stainless Steel

Duplex stainless steels are iron, nickel, and chromium (Fe-Ni-Cr) alloys. They are a popular grade in the stainless-steel family, and consist of two-phases in their metallurgical structure, that is, both the austenite and ferrite in equal proportions. Hence, they get their name from the austenite-ferrite micro-structure. They are useful in applications that require good corrosion resistance and strength.

Alloy 2205 duplex pipe finds varied use in different industries. It is typically used in applications for chemical processing, transfer, and storage, and in those systems that are subject to high stresses in chloride-containing environment. These pipes help to transport oil and gas, and also forms a part of heat exchangers and hydraulic tubing systems. The conception of duplex stainless steel was wrought on in the early 1930s.Duplex stainless steels has a chromium content of 22%–25%, with the additional presence of molybdenum, tungsten, and nitrogen. The alloy of austenite-ferrite in its microstructure imparts it a favorable combination of the parent grades.

This article lists the important aspects of duplex stainless-steel pipes.

Stress Corrosion Cracking (Scc) Resistance

SCC is the growth of cracks due to the effect of static and tensile stress in reactive environments. As duplex stainless steel pipe have higher strength and better toughness than ferritic grades, it does not succumb to SCC. It possesses good mechanical properties and shows excellent resistance to corrosion. The higher resistance to SCC is because of its microstructure, which makes it more difficult for a crack in duplex systems.

Fabrication And Welding

Duplex alloys have low risks of hydrogen cracking, and are more resistant to solidification cracking as compared to austenitic grades. It shows easy welding and machining, enabling welding with relatively high heat input and low interpass temperatures. Welding duplex stainless steel is cheaper and easier, and one can use various welding methods like resistance welding, laser welding, and electron beam welding for forming the desired shape.

Different Forms of Duplex Stainless Steel

Based on the presence of different production methods, there can be four basic duplex forms. Lean Duplex has lower Nickel content, and does not contain molybdenum. It is mainly used in storage tank construction. 2205 duplex stainless steel is regular duplex possessing standard amounts of both nickel and molybdenum and finds wide use in pharmaceutical sector. Super Duplex has higher molybdenum and chromium (24-26%) content, and is used for constructing pipes for oil, gas, and chemical industries. Hyper Duplex contains even higher volumes of molybdenum and chromium (27-32%), and finds use in energy and oil sectors.

Cleaning Duplex Stainless Steel

Different fabrication and welding processes can damage duplex stainless steel pipes which can damage its structure. For protecting the steel surface against formation of rust and other impurities, one needs to clean the steel surface before and after welding. Electrochemical cleaning, manual grinding, chemical pickling are common methods for cleaning the surface and restoring the passivation layer that imparts anti-corrosive properties to the structure. It helps to take care of the common side-effects such as oxidation and heat tinting that occurs during the welding process.

To Conclude:

These are some of the important properties that characterize the duplex stainless steel grade. It is a highly valuable with enhanced properties such as improved weldability, good toughness, and corrosion resistance, which makes it a useful material in different industries.

6 Reasons to Choose Nickel Alloy

Nickel alloys are metals that can be combined with other elements to create durable, high-quality materials. Alloys often combine different types of nickel which act as the base metal and help maintain desirable properties like corrosion resistance. Nickel alloys have many uses, including coins, gas tanks for vehicles, aircraft engines parts, medical devices and more.

Nickel alloy 20 tubing is one kind of stainless steel that’s resistant to high temperature. Nickel iron alloy is used at places where a low rate of thermal expansion is required. Nickel copper alloy is used in marine procedures as it offers corrosion resistance from salty water or seawater. Nickel chromium iron alloy is used to produce alloy that can assist in oxidation together with high-temperature corrosion. Nickel molybdenum alloy provides high chemical resistance from hydrochloric acid, sulfuric acid and other strong acids.

The Nickle alloys are also known as the ni-based superalloys.This is because of the amazing strength
and resistance this material holds. The chemical substances added to this material are cabalt, tangsten
iron, chromium and molybdenum. There are a lot of reasons for which industries prefer using nickel-based
alloys. Adding nickel to various metals brings changes in the nickel alloy 20 tubing properties after the procedure.

06 Tips To Buy Stainless Steel Pipe

A stainless steel pipe is a great option for industrial settings. It’s durable, long-lasting and rust-resistant – perfect if the environment you’ll be using it intends to have high humidity or water exposure issues. In addition, they are not easily corroded and can withstand high pressures. When choosing an industrial supplier of stainless steel pipes, make sure they have plenty of experience with their product line and are licensed.

If you’re looking to buy stainless steel pipe for industrial settings, it’s important to consider the material used. Always make sure that the material used is corrosion-resistant. The best way to ensure longevity and durability in your piping is by using 304 or 316 aluminum materials that are highly resistant to rusting. In addition, a buyer should consider the price of stainless steel pipe before making any purchases. The price fluctuates greatly, so be mindful and do your research on various prices to find what best suits you.

3 Causes Of Corrosion Of Stainless Steel Tubes

While stainless steel can resist corrosion better than carbon and steel alloys, certain conditions can affect the integrity of the material over time. For example, as it comes in contact with an electrolyte such as water, oxygen, or other metal, it causes a chemical reaction, due to which it can lose electrons and become weak. Hence, it renders the stainless-steel product vulnerable and can succumb to rust, cracks, and holes, due to which it can collapse.

Stainless steel corrosion is of different types. Uniform corrosion spreads evenly across the surface of stainless steel material and causes a uniform metal loss across the entire surface. Pitting corrosion is a form of localized corrosion occurring in a confined area in pits and spots due to exposure to aggressive chemical species like chloride, which can cause oxide breaks on the metal. Finally, crevice corrosion in stainless steel occurs in the microenvironment where there is a difference in ion concentration between two metal areas.

Intergranular corrosion is a form of selective attack in the vicinity of grain boundaries in stainless steel. It can severely affect the mechanical properties of the metal. Tensile stress and a specific corrosive environment can also crack stainless steel and can result in axial cracks in the pipeline. The fine cracks may emerge in the microstructure of the metal, and hence it is hard to spot.

To prevent the metal integrity of your 416 stainless steel tube and other stainless steel grades, you need to protect the metal against these corrosive atmospheres that can critically affect its lifespan.


The chromium content of stainless steel alloys is vulnerable to chlorides. In wet and humid environments that contain chloride ions, it can cause pitting corrosion and crevice corrosion in the stainless steel tubes. Chloride breaks down the passive film on the surface of stainless steel. Corrosion accelerates in an alkaline environment and coastal areas with salt-spray exposure, resulting in the rusting of the metal.


While stainless steel is resistant to acidic corrosion, strong acids can destabilize the passive layer on the stainless steel surface. Intermediate concentrations of sulfuric acid and hydrochloric acid can cause surface corrosion. These are strong reducing acids and, when present in higher concentrations, can trigger the degradation of stainless steel.

Iron And Carbon Steel Particles

Iron and carbon steel particles can deposit on the surface steel and damage the oxide layer. At the site of contamination, it can produce localized or pitting corrosion. The rust spots can compromise the chromium oxide surface of the stainless steel tubes. Carbon contamination of stainless steel can occur due to the breakdown of organic materials when exposed to materials from nearby welding, combustion of sooty gas flames, or because of paint, pen, or pencil markings.

To Conclude:

To ensure the longevity of your stainless steel tubes, you need to protect and prevent contact with corrosive substances. Stainless steel requires minimum maintenance, and following the best practices, keep the integrity of the protective covering of stainless steel intact to avoid any form of rusting in various environments.

5 Tips For Cleaning Stainless Steel Tubes

Stainless steel tubes require cleaning at regular intervals for effective maintenance of their integrity.You can educate about the signs of contamination, corrosion, and surface degradation of stainless steel to determine what degree of cleaning and care it requires.To establish the best cleaning criteria, you need to identify the scope and objectives of your cleaning process by carefully inspecting the stainless steel tubes. Accordingly, you need to deploy the best cleaning practices that adhere to the industry standards defined for the custom-built stainless steel tubes.

The surface of stainless steel tubes has a thin layer of chromium oxide which protects the metal from corrosion. The alloy’s chromium content combines with oxygen from the atmosphere to form the passive layer of chromium oxide. Various contaminants can get trapped within the passive film and can severely affect its corrosion resistance properties. Hence, stainless steel products require regular cleaning to prevent corrosion and protect the luster of the surface.

The various types of pipe contamination for 316 stainless steel tubes and other grades are dirt, iron contamination, deposition of oil, paint, grease, and rust. For cleaning stainless steel tubes, you can refer to the following.

Routine Cleaning

To carry out routine cleaning of stainless steel tubes, you can clean them with soap, mild detergent, or ammonia solutions in warm water. You can apply any of these agents with a soft cloth or nylon sponge. After this, you need to rinse and dry it with a soft cloth. It helps to remove ordinary soiling. While cleaning stainless steel, use mild non-scratching abrasive powders, and avoid using standard carbon steel brushes or steel wool. It can leave articles embedded on the surface, which can trigger rusting.

Solvent Cleaning

You can use organic solvents to remove stains that are fresh and have not yet oxidized or decomposed. The solvent should not contain chlorine, like acetone, methyl alcohol, and mineral spirits. You can immerse smaller articles into the solvents or use the vapor cleaning method to control the discharge of solvents. Wipe it post-cleaning.

For Moderate Soiling

You can use a mild abrasive cleaner for moderate soiling and light staining and use a soft cloth, nylon scouring pad, or a soft bristle brush. In the direction of the polished finish, use the material to make long, even strokes. You need to avoid using a circular rubbing action. After you clean it, you need to rinse and dry-wipe to complete the process and remove water stains.

For Heavier Soiling

For more intense staining and heavy soiling, you can use ammonia solution or warm/hot detergents. You can also use acidic cleaners and follow the cleaning procedures mentioned for moderate soiling.

Passivating Treatment

To maximize the corrosion resistance capability of stainless steel and remove surface contaminants, you can use the passivation treatment. First, you need to clean the stainless steel surface thoroughly and remove the pollutants. After this, you need to enter the metal in a passivating acid bath. Depending on the chromium content and the machinability properties of the stainless steel grade, the nature of the passivation treatment will vary.

To Conclude:

While selecting the cleaning practices for stainless steel tubes, you need to carefully analyze the potential of the cleaning agent to counter the contamination or corrosion. Proper routine care can extend the lifespan of stainless steel.

4 Things You Should Know About Hastelloy C276

Hastelloy C276 is a nickel-molybdenum- chromium wrought alloy with a small amount of tungsten. It is widely used in the chemical process and associated industries. It is available in various commercial markets, such as plates, sheets, strips, wires, pipes, tubes, and covered electrodes.

Hastelloy C276 offers reliable performance, making it suitable for geothermal, solar energy, oil and gas, and pharmaceutical industries. Hastelloy C276 tubing shows high resistance to many aggressive chemicals. As it has high chromium, molybdenum, and tungsten content, the alloy conveys exceptional resistance to pitting and crevice corrosion in reducing environments. The chromium content allows it to show resistance to oxidizing media. It is considered the most versatile corrosion-resistant alloy available. Hastelloy C276 can withstand the corrosive effects of wet chlorine gas, hypochlorite, and chlorine dioxide.

Here are a few essential features, characteristics, and applications of Hastelloy C276-


Hastelloy C276 is used in reactors, heat exchangers, and columns in the chemical process industry (CPI). The superalloy is well suited to many industrial processes. It is also used in the petrochemical, oil and gas, and pharmaceutical industries. It is used to recover “sour” natural gas and for the desulphurization of flue gas equipment. Hastelloy C276 also finds use in pollution control, pulp and paper production, water desalination, and municipal waste treatment plants.


The nickel-chromium-molybdenum content in the superalloy alleviates concern over the welding. Hastelloy C276 can be welded easily by the commonly used welding methods. It is malleable, easy to form and weld. In the welding process, you need to avoid excessive heat input. You can use the superalloy in “as-welded” conditions for corrosive applications without applying any more heat treatment.

Resistance Properties

Hastelloy C276 shows resistance to chloride-induced stress corrosion cracking. It also offers resistance to seawater crevice corrosion. Hastelloy C-276 alloy exhibits high resistance to chloride-induced pitting and crevice attack. It also has excellent resistance to critical inorganic acids, even in its welded form. The chromium-molybdenum content allows it to show opposition to both oxidizing and non-oxidizing acids. It can also resist robust solutions of oxidizing salts, such as ferric and cupric chlorides.

Heat Treatment

The wrought forms of the superalloy are generally furnished in the heat-treated condition. Annealing for Hastelloy C276 is done at a temperature between 2050°F and 2150°F. The alloy can be hot forged, hot rolled, hot upset, hot extruded, and hot-formed. For hot forming, the specified temperature range is 1600 and 2250°F, and heavy forming at a temperature above 2000°F. The cold-worked parts should be re-annealed to optimize their corrosion resistance properties. The superalloy uses conventional cold working procedures for hard-working purposes. It can be cold-formed using deep drawing, press forming, and punching.

To Conclude:

Hastelloy C276 is a versatile material, and its strong resistance properties render it useful in many industries. It shows excellent corrosion resistance in reducing environments and aggressive media, good machinability, fabrication, and weldability, making it suitable for varied uses.

An Essential Guide on Benefits and Applications of C276 Pipes

Alloy C276 pipe is made from a nickel-molybdenum-chromium alloy with tungsten addition that has good corrosion resistance in various harsh situations. Because of the high molybdenum content, this alloy is particularly resistant to pitting and crevice corrosion. The low carbon content reduces carbide precipitation during welding, preserving corrosion resistance in as-welded structures.

In a range of severe conditions and media, Alloy C-276 has exceptional corrosion resistance. It’s ductile, like many other nickel alloys, and can be easily shaped and welded. In most industrial applications where harsh chemical conditions exist, and other alloys have failed, this alloy is used.

The pulp and paper business employs wood as a key raw resource to produce high-quality pulp, paper, and other cellulose using the proper bleaching vessels and digesters. Wood pulp is bleached when you use the bleaching vessels, and the strongest appears whiter. On the other hand, Digesters are made of wood chips burned to a high temperature with sodium hydroxides and even sodium sulfide to modify the pulp by dissolving the lignin binder dramatically. White and back liquors are corrosive substances in cooking that can damage the wall of the interior parts.

Chloride, as well as chlorine-dependent compounds, are used in the above process. On the other hand, Hastelloy alloy c276 pipe and tube develop first-class corrosion resistance in the great majority of chloride environments. It has both acidic and alkaline properties, making it the optimum choice for vessel bleaching and digester content.

What is Hastelloy?

Nickel-molybdenum alloy Hastelloy is a nickel-molybdenum alloy. Hastelloy comes in a variety of grades, several of which are nickel-chromium-molybdenum alloys. Each of these grades has been tailored for a distinct application, although they are all corrosion-resistant. Hastelloy is made tougher by molybdenum, which makes it stronger at high temperatures and ideal for welding. These alloys are simple to work with and form. They may be forged, and cold worked, and have high ductility.

Hastelloy is a suitable choice for moderate to severe corrosive conditions because of its remarkable resistance to severely oxidizing and reducing chemicals. In the chemical processing and petrochemical industries, it is often used for pipes and valves. It’s also great for pressure vessels and heat exchangers, and it’s utilized in nuclear and chemical reactors.

Industries and applications of c 276 alloy

Chemical and petrochemical processing, oil and gas, power generating, pharmaceutical, pulp, paper production, and wastewater treatment are just a few industries that use alloy C-276. Stack liners, ducts, dampers, scrubbers, stack gas reheaters, heat exchangers, reaction vessels, evaporators, transfer pipework, and many other highly corrosive applications are among the end-use applications.

Because C276 pipe comes in various shapes and sizes, including bar, plate, pipe fittings, welding wire, pipe, and tube, it would be easier for industries to use it for a variety of purposes. It refers to the number of corrosion-resistant flexible alloys available on the market. It offers great resistance to a wide range of chemical processes, including ferric and cupric chloride, hypochlorite, and other brine, without posing any harm. It has a low carbon content, which helps prevent grain boundary carbide precipitation during welding, preserving the heat component of the welded joints’ corrosion resistance. This resistance is against localized cracking, pitting, and stress corrosion cracking, among other things.

Infographic: 06 Tips To Choose The Best Stainless Steel Tube

There are many factors you should consider when selecting stainless steel tube. The main requirement for stainless steels is that it should be corrosion resistant for a specified application or environment. Strength and fabrication characteristics are also taken into consideration. Make sure the material used to make the stainless steel tube is safe to use at various temperatures.

Consider the quality of the 316 stainless steel tube or any other tube you want. Make sure that your supplier agrees to deliver the product at your said location. Ask if you can buy the quantity you need, and is there any restriction? Ensure the supplier has the variety of stainless steel tubes that you need to buy. Make sure to choose a corrosion-resistant material well-suited to its application reduces maintenance, downtime, and replacement costs.

Infographic: 07 Reasons Why Aeronautics Industry Uses 321 Stainless Steel Tube

Aeronautic expert engineers prefer 321 stainless steel tubes for use in different parts of the aircraft. Aircraft engines have to deal with extreme temperature changes as high as 1500 degrees Fahrenheit. 321 is a solid alloy that can be used at such temperatures. It can also be used at low temperatures without affecting the aircraft’s performance or reducing its life span.

Aircraft operate under high pressure, which severely tests their tensile strength. This needs that the materials used in specific areas should be strong, so stainless steel tube is the far better option. When dealing with 321 stainless steel tube, engineers can be sure that they will not find signs of fatigue as this alloy can withstand different temperatures and remain free from cracks. Corrosion-resistant is another quality of stainless steel; 321 is ideal for use in critical areas of an aircraft exposed to the elements.

The Versatility of Stainless-Steel Tubes

Steel can be used to create a versatile alloy known as stainless steel. The addition of chromium to it helps increase corrosion resistance, which is what has given stainless steel its name. Stainless steel pipes are of so many types that it may be confusing to pick the right one for a business application. It is possible to find stainless steel tube in a wide range of sizes and designs.

In most cases, tubing creates a round image, but here stainless steel tube is available in different shapes, ranging from rectangular and round to oval and flat bars. Different stainless steel tubes have variable measurement protocols. Here is the classification according to size:

  • Metric/Square/Fractional – This type of stainless-steel tubing is denoted by its wall thickness or OD (Outside Diameter). The three types of classifications have different sizes. Square tubing is highly suitable for many commercial applications due to its mechanical properties such as architectural appeal, strength, and capacity to withstand extreme weather.
  • Hypodermic – This tubing is commonly seen in several medical and industrial applications. It is known for easy use and ease of cleanliness. Hypodermic needles are generally found to be made of grade 304 stainless steel tubing, which allows good quality finish through thin wall tubing.

Industry Applications

Stainless steel tubing is popularly being used across several industries. These industries are just as diverse as the total number of tubing components in use. Here are some examples:

  • Airlines – Aircraft hydraulic lifts use tubes that comprise of high chromium and nickel percentages
  • Mills and Manufacturing Lines – Stainless steel is being used in machinery here
  • Automotive – High quality mufflers are prepared by using stainless steel tubes
  • Heat and Gas Lines – Stainless steel tubes here help them withstand extreme pressure

Defense, aerospace, and several consumer industries purchase robust steel tubes made using rugged alloys like stainless steel. As per corrosion and temperature needs of clients, composition of material is altered.

Is 304 Stainless Steel Pipe a Good Choice?

For most piping and tubing applications, 304 stainless steel pipes are greatly suitable due to their high resistance to chemicals and corrosion. However, this variety is not compatible with applications where temperatures drop between 800-1640 F as it is susceptible to carbide precipitation. 304L is able to overcome this problem by virtue of a lower carbon content limit, making it suitable for welding and applications of higher temperatures.

General Corrosion Resistance

Stainless steel tubing made from general category steel is appropriate for applications where corrosion resistance is the greatest requirement. Stainless steel which has high nickel and chromium contents will be able to offer the highest amount of resistance here.  

Stainless steel tubing can also be used in contact with sensitive products like food. For all applications like these, sanitization is always the highest priority. Since stainless steel tubing does not tarnish, possesses high corrosion resistance, and can be easily kept clean, it is suitable for sanitary purposes like this.

For purchasing stainless steel tubes, businesses must remember to get in touch with reputed companies with several years of experience.