Duplex Stainless Steel

Importance Feature of Duplex Stainless Steel

Duplex stainless steel is ferritic-austenitic steels which contain high levels of chromium and nitrogen. These materials make them highly resistant to localized and uniform corrosion. Duplex stainless steel offers excellent resistance against crevice and pitting corrosion. It has adequate strength and weldability. This type of stainless steel has low thermal expansion which makes them the right choice for applications that involves extreme temperature variations.

There are a few essential features of Duplex Stainless Steel such as:

  • Strength: Super Duplex Steel S31803 Tubes have almost doubled strength than conventional ferritic or austenitic stainless steels. This excellent strength makes it perfect for manufacturing widely demanded industrial products.
  • Ductility: It has significantly better ductility and toughness than ferritic grades; however. Because of its toughness, Duplex Stainless Steel is used in high-pressure applications in many industrial sectors.
  • Fabrication and welding: Duplex Steel can be easily welded and is also convenient for the fabrication process. This makes it cheaper than other stainless steel materials.
  • Corrosion resistance: Corrosion resistance property depends on the composition of materials. Duplex Steel has molybdenum, chromium, and nitrogen which make it stronger to resist pitting and crevice corrosion.
  • Stress corrosion cracking resistance: Duplex stainless steels have better stress corrosion cracking resistance ability which is acquired from the ferritic side. This ability is making it sturdier and more durable.
  • Cost: Duplex stainless steels contain lower nickel and molybdenum. Because of cheaper alloying materials, duplex stainless steel is more economical in price. It is widely available in different grades and alloying combinations which makes it convenient to choose for fabrication.

Apart from all these essential features, Duplex Stainless Steel has many standard features such as it has excellent strength and being very difficult to break. Hence it is used in several complicated applications. It has an incredible tensile strength which makes it superior in all types of standard steels. Its elastic limit is twice that of other types of steel like austenitic. Duplex Stainless Steel has high mechanical strength, higher tenacity than that ferritic steel, low thermal expansion, excellent hardness, suitable for heat treatment, superior workability, and perfect weldability than ferritic steel. All these features make Duplex Stainless Steel a more useful and selective material.

Stainless Steel Fasteners

Different Grades of Stainless Steel Fasteners Explained

For improved corrosion characteristics, stainless steel is an alloy of low carbon steel and chromium. Stainless steel is for the price, highly corrosion resistant. As the anti-corrosive properties of the metal are intrinsic, if scratched during installation or use, it will not lose this resistance.

That stainless steel is stronger than standard steel is a common misconception. Many stainless steel alloys cannot be hardened by heat treatment due to their low carbon content. Therefore the stainless alloys used in bolts are marginally stronger than un-hardened steel relative to ordinary steel but considerably weaker than hardened steel fasteners. Stainless fasteners are prone to seizing up during installation, a condition known as galling unless great care is taken. While some grades are slightly magnetic, most stainless steel fasteners are much less magnetic than standard steel fasteners.

What are the different grades of Stainless Steel Fasteners?

 18-8 Stainless Steel Fastener

304-grade stainless steel, which is the most commonly used and versatile austenitic type of stainless steel, is 18/8 stainless steel. The 18/8 numbers reflect the 18 percent chromium and 8 percent nickel composition of this steel, making it very resistant to corrosion and oxidation. 18/8 stainless steel is also very durable and can easily be made. It is quick to clean the metal and it is available in several appearances and finishes.

Stainless Steel 316 Fastener

The 316 grade is a molybdenum-bearing austenitic stainless steel that contains 8% nickel, 18% chromium, and 2-3% molybdenum. The higher nickel and molybdenum content enables this grade to display better overall corrosion resistant properties which are particularly true in chloride environments in pitting and crevice corrosion. Moreover, Alloy 316 offers outstanding strengths of high temperature tensile and stress rupture, as well as outstanding weldability. Like 316 stainless steel screws, 316 stainless steel washers, and 316 stainless steel nuts, Fastener Solutions offers this alloy grade.

 Stainless Steel 410 Fastener

SS 410 Fasteners are used where the ideal stiffness, air or furnace cooling is tempered. Furthermore, the tempering of our Alloy 410 Fasteners in the 750 Degree F-1050 Degree F range results in reduced impact strength and slightly decreased corrosion resistance. For petroleum fractionating systems, bolts, screws, bushings and nuts, shafts, pumps and valves, gas turbines, mine ladder rungs, and so on, these Grade 410 fasteners are also used.

In both the annealed and hardened settings, our Type 410 Fasteners are magnetic and are typically used for applications involving mild corrosion, high strength, and heat resistance. Slow regulated cooling from 1500 degrees F / 1600 degrees F for solution annealing and heat to 1700 degrees F / 1850 degrees F for hardening of AISI 410 fasteners, after quenching in air or oil. By all standard methods, the 410 Stainless Steel Fasteners are readily welded, where post-weld annealing is recommended to ensure optimum ductility.

Stainless Steel Fasteners

What Are the Varying Grades of Stainless Steel Fasteners?

Stainless steel is a low carbon steel and chromium content but offers high corrosion resistance. Stainless steel, because of its stability, strength and anti-corrosive and high heat properties, is one of the most popular materials used for fasteners. A flexible, economical alloy benefits from the combination of steel strength with its superior anti-corrosion and heat-resistance properties.

You will find the following types while looking for robust and effective grades of stainless steel fasteners in the market.

Grade 18-8

The Stainless Steel 18-8 grade is also referred to as 304 SS for their chemical composition is same in both 18-8 & 304 Stainless Steel. As the name suggests, the grade 18-8 consists of 18% chromium, and 8% nickel which makes it an excellent resistance to corrosion. When it comes to 304 grade, it is splitted into two grades, which are 304L and 304H depending upon their carbon content. Again as the name denotes, 304H is high carbon grade and 304L is a low carbon grade. The Stainless Steel 304 or 18-8 stainless steel has high corrosion resistance, is stronger than mild steels and has less heat sensitivity than 302 grade.

Grade 316

 The composition of the alloy is one of the reasons that the Type 316 Stainless Steel Fasteners have stronger mechanical and physical properties. Stainless Steel Fasteners Grade 316 are intended for applications under harsh environmental conditions. These industries therefore need better protection and an improved resistance to corrosion provided by the stainless steel series of 300 grades.

Grade 304 (18-8)

Grade 304 possesses an excellent combination of corrosion resistance, strength and fabricability. Stainless Steel Fasteners of this grade are being extensively used in almost every industry today.

Grade 304 is suitable for use in sinks, table tops, urns, stoves and various appliances because of its tolerance to food, inorganic chemicals and most organic chemicals. In the brewing and food processing industries, fasteners of this type are also used.

We provide top quality Stainless Steel and marine grade fasteners in the world of steel. Our 18-8, 304 or 316 grade stainless steel fasteners offer exceptional durability and best quality. We hope this article was helpful to you to understand the different grades of Stainless Steel fasteners.

Stainless Steel Seamless Pipes

Stainless Steel Seamless Pipes: Uses and Applications

Stainless Steel Seamless pipes are common and can be found in residential walls, labs, and commercial and industrial facilities underground and inside them. Fluids including water, natural gas, waste and air are conveyed by seamless steel pipes. In order to manufacture steel pipes, three manufacturing methods exist.

Stainless steel Seamless pipes are made by using an extrusion mold. These Stainless steel seamless pipes are considerably affordable. Casting is the third method. Through a casting mould, molten steel is poured.

The preferred alternative for processes in the following conditions is our steel pipes and tubes:

  • violent media (e.g. lye and acid)
  • elevated temperatures
  • and / or elevated pressure

They call for the use of products of high quality.

Uses and Applications

Heat exchanger

A heat exchanger is a piece of equipment designed from one medium to another for efficient heat transfer. The application areas of the Stainless Steel Seamless pipes: Heat Exchanger Tube specifically cover the following: Apparatuses and heat exchangers for piping systems.

Fertilizer industry

The areas of application in the fertiliser industry primarily include the following: Melamine plants high-pressure tubes and piping systems apparatus and heat exchangers of urea synthesis ethylene plants.

Chemical and petrochemical industry

The fields of operation in the chemical and petrochemical industries primarily include the following: Melamine plants high-pressure tubes and piping systems apparatus and heat exchangers of urea synthesis ethylene plants.

 Power generation and Environmental technologies

Our tubes and pipes are used mainly for heat exchangers in power plants and the energy sector. Environmental systems and waste incineration plants also have the same field of application: reheater superheaters.

 Develop ship-building for international clients

In the fields of discovery, manufacturing and processing, we develop tubes for shipbuilding. Stainless Steel 304 Pipes for use in ship construction.

Oil and gas applications 

SS Seamless steel pipes for oil casing and tubing for offshore and onshore Oil & Gas applications in the domains of Production, Exploration and Processing.

Mechanical and plant engineering and construction

Our pipes are primarily used in mechanical and plant engineering and construction in the following areas: food manufacturing, automobile technology, measurement and control technology, pumps, hydraulic cylinders, etc. Stainless Steel Seamless pipes is known as a half-finished product for fittings and tubes and pipes of flange output as a half-finished product for radially machined parts.

Automotive industry

In the automotive field, DMV products are used especially in the following areas: Other important areas of use are hydraulic braking systems.

Stainless Steel Seamless pipes for project service 

The SS Seamless pipes are used in petroleum, Connecting water, gas and other common fluids. Seamless steel pipes are common and can be found in residential walls, labs, and commercial and industrial structures underground and inside them.

Stainless Steel Seamless pipes for high temperature and pressure service 

For high temperature and pressure operation, we sell a comprehensive range of Seamless steel pipes. The SS Seamless pipes are also used in the applications like containers, heating pipelines, and high temperature reheaters.

 

Stainless Steel Fasteners

Different Grades of Stainless Steel Fasteners

In this day and age, one of the most common materials from which fasteners are made is stainless steel. ASTM A193 Stainless Steel Fasteners are extremely ubiquitous these days. However, most people who use them are usually not familiar with the characteristics of stainless steel as a material used to build fasteners. It’s important for you to gain even a basic understanding of how this material works so that you can then figure out how to take advantage of it in any project. It’s also a good idea to know of the different types of stainless steel that are available, and what their applications are.

Why is stainless steel so popular?

Over the past few years, the use of stainless steel has become more common. This is mainly due to the fact that it’s not only resistant to corrosion, but can also maintain its strength even when subjected to very high temperatures. Any material made from stainless steel is likely to last very long in most environments regardless of humidity levels or any other factors that might increase the risk of rusting, such as the presence of saline water. Some of the common industries in which stainless steel fasteners are used include architecture, automotive design and the design of electronics.

The types of stainless steel you are likely to come across

When you are buying stainless steel fasteners, it would be a idea for you to understand that there are many different subtypes available. Knowing about each will make it much easier for you to determine which one to use for a particular application. Some of the most common include:

Type 304: This is one of the most common types of stainless steel in the industry. In fact, more than half the stainless steel produced in the world is made of this type. Type 304 stainless steel is usually designed to withstand ordinary corrosion, and is designated as austenitic (contains chromium and nickel).

Type 316: Type 316 stainless steel is also austenitic. However, it contains an additional 2 to 3 percent of Molybdenum in addition to the chromium and nickel. This makes it much stronger compared to type 304 stainless steel. The addition of Molybdenum in the alloy also makes it a bit more expensive as well.

Type 409: This is technically known as a ferric type of stainless steel. It contains plain chromium and is well known for resisting very high temperatures. It also happens to have the lowest grade of chromium in all types of stainless steel, and is, for this reason, one of the cheapest you can find.

Type 410: This is martensitic stainless steel, which means that it contains plain chromium. This makes it particularly strong. It’s also cheap and heat treatable and is also non-corrosive. Due to all these features, it’s the most ideal type of steel used in heavy-duty settings.

Type 430: SS 430 Fasteners is also very commonly used. It’s ferritic stainless steel and has features of resistance against corrosion. It’s mostly used for decorative purposes.

Seamless Tube

What is ASTM A312 Stainless Steel?

Overview

ASTM A312 is an American Standard specification which covers seamless, straight-seam welded, and heavily cold worked welded austenitic stainless steel pipe intended for high-temperature and general corrosive service. The most common grades are 304/304L Stainless Steel and 316/316L Stainless Steel .In this article, we illustrate the chemical and mechanical properties of the A312 specifications.

ASTM A312 STAINLESS STEEL PIPE 

Stainless steel pipes are used for high-temperature applications where corrosion is a key issue.

Stainless steel has been developed to cope with the increasing demand, across many industries, for more durable steels that could withstand demanding service conditions. Stainless steel was conceived as an evolution of standard carbon steel and obtained by adding alloying elements to the base iron like Nickel and Chromium. The addition of such alloying elements enhances the resistance of the steel to corrosion in harsh applications.

Before learning about the different grades, let’s review the types of stainless steel available on the market and their classification.

We are Leading Manufacturers, Suppliers & Exporters of ASTM A312 Stainless Steel Pipes in India.

STAINLESS STEEL TYPES

As a general rule, any steel alloy that has at least 10.5 percent of chromium may be considered stainless steel. However, a multitude of grades is available depending on the mix of the alloying elements (Nickel. Chromium, Moly, Titanium, Copper, Nitrogen, etc.) Each alloy has a specific structure and chemical and mechanical properties.

The general attribute of stainless steels is that they show resistance to corrosion thanks to an outer chromium oxide layer. Such oxide acts like a microscopic protection layer that reacts with oxygen and blocks corrosion. Further, stainless steel alloys feature better toughness in cryogenic applications than carbon steel, better strength and hardness, improved ductility and low maintenance costs.

Stainless steels may be grouped into a few families, designated as “series”. Let’s take a closer look.

Austenitic Stainless Steel (Series 300)

These are the most common grades of stainless steel. The microstructure of austenitic stainless steels is obtained with the addition of nickel, manganese, and nitrogen that give weldability and formability properties to the alloy. The resistance to corrosion can be further improved by augmenting the percentage of chrome, moly, and nitrogen to the base alloy.

Nevertheless, the basic austenitic grades are vulnerable to stress corrosion cracking (higher percentages of nickel are necessary to enhance the stress corrosion cracking). Austenitic stainless steel cannot be hardened by heat treatment but have can work-hardened to high strength levels while retaining a reasonable level of strength and ductility.

Even if austenitic steels are generally non-magnetic, they can show some magnetic property based on the actual alloy composition and the work hardening given during production. Austenitic stainless steels are divided into the series 200 (chromium-manganese-nickel alloys) and 300 (chromium-nickel alloys like 304, 309, 316, 321, 347, etc). Stainless Steel 304 Pipes is the most common austenitic stainless steel that suits most corrosive applications. Any other grade in the 300 series enhances the basic features of SS304.

Martensitic Stainless Steel (Series 400)

Martensitic stainless steels are similar to ferritic steels as they both have remarkable chromium content, however, martensitic steels have higher carbon content up to 1 percent. The high carbon content allows martensitic steels to be hardened and tempered as standard carbon and chrome alloy steels (but show generally low weldability and ductility). This type of stainless steel is specified in case of high strength and moderate corrosion resistance requirements. Different from standard austenitic stainless steels, martensitic grades are magnetic. Common martensitic grades are 410, 420 and 440C.

Ferritic Stainless Steel (SS430)

Ferritic stainless steels have significant chrome content but low additions on carbon (generally below 0.1 percent). The name of this family of stainless steels comes from the fact that their microstructure is quite similar to carbon and low alloy steels.

These steels have a wide range of application, except for thin surfaces as they have a low resistance to welding or applications requiring formability (ferritic steels show low formability and ductility). Ferritic stainless steels cannot be hardened by heat treatment. By adding moly to a ferritic grade, the steel can be used in highly aggressive applications like desalination plants and seawater. These steel show also remarkable resistance to stress corrosion cracking. Likewise martensitic steels, ferritic SS is magnetic. The most common ferritic grades are the 430 (17 percent chromium), and the 409 (11 percent chromium), largely used in the automotive sector.

Precipitation hardening (PH 17-4)

PH steels can feature remarkable strength due to the addition, in the alloy, of elements as copper, niobium, and aluminum. These steels can be machined to very specific shapes with high tolerances requirements before the final aging treatment. This is different from conventional hardening and tempering of martensitic steels that are subject to distortion during the treatment.

The resistance to corrosion of precipitation hardening steels is comparable to standard austenitic steels like SS304. The most common precipitation hardening stainless steel is the 17-4PH, which features 17 percent chromium and 4 percent nickel.

ASTM A312 PIPE DIMENSIONS

The standard stainless steel pipes dimensions are set by the ANSI ASME B36.19 specification. Seamless SS pipes are available in the size range 1/8″ thru 24″, welded stainless pipes are manufactured in the range 2″ thru 36″ (ASTM A312 Pipes i.e. electric-fusion-welded austenitic chromium-nickel stainless steel pipe, or as rolled).

SS 304 Sheets

What’s The Difference between 304 and 316 Stainless Steel?

When choosing stainless steel that must withstand corrosive environments, austenitic stainless steel is typically used. Austenitic Stainless Steel has excellent mechanical properties, the high amounts of nickel and chromium in austenitic stainless steels also provide outstanding corrosion resistance. Additionally, many austenitic stainless steels are formable and easily weldable. SS 304 and SS 316 are the two of the more commonly used grades of austenitic stainless steel. This blog will examine the difference between stainless steel 304 and stainless steel 316, to help you determine which grade is right for your project.

Grade 304 stainless steel

304 stainless steel is generally regarded as the most common austenitic stainless steel. It contains high nickel content that is typically between 8 to 10.5 percent by weight and a high amount of chromium at approximately 18 to 20 percent by weight. Other major alloying elements include carbon, manganese, and silicon. The remainder of the chemical composition is mainly iron.

Stainless Steel 304 has excellent corrosion resistance because of the high amounts of nickel and chromium. Common applications of stainless steel 304 include:

  • Appliances such as refrigerators and dishwashers
  • Commercial food processing equipment
  • Fasteners
  • Piping
  • Heat exchangers
  • Structures in environments that would corrode standard carbon steel.

316 Stainless Steel

Grade 316 stainless steel has high amounts of chromium and nickel, similar to 304. SS 316 also contains silicon, manganese, and carbon, with the majority of the composition being iron. A major difference between stainless steel 304 and stainless steel 316 is the chemical composition, with Grade 316 containing a significant amount of molybdenum; typically 2 to 3 percent by weight whereas only trace amounts of molybdenum are found in 304. Grade 316 possesses increased corrosion resistance due to higher molybdenum content.

When selecting austenitic stainless steel for marine applications Stainless Steel 316 is often considered one of the most suitable choices. Other common applications of 316 stainless steel include:

  • Chemical processing and storage equipment.
  • Refinery equipment
  • Medical devices
  • Marine environments, especially those with chlorides present

Which Should You Use: Grade 304 or Grade 316?

Situations where 304 stainless steel may be the better choice:

  • If the application requires excellent formability, the higher molybdenum content in Grade 316 can have adverse effects on formability and hence SS 304 grade may be used.
  • The application has cost concerns. Grade 304 is typically more affordable than Grade 316.

Situations where 316 stainless steel may be the better choice:

  • If the environment includes a high amount of corrosive elements.
  • If the material will be placed underwater or be exposed to water consistently.
  • In applications where greater strength and hardness are required SS 316 grade should be used.

Both these grades are available in various forms like Stainless Steel 304 Pipes, Stainless Steel 304 Plate, Stainless Steel 316 Pipes, Stainless Steel 316 Plates, etc. Both the grades are visibly same and very difficult to differentiate due to lack of visible difference between two identical pieces of different grades hence one should ask the Stainless Steel 304 Pipes Supplier to provide them material test report (MTR) of the actual material to validate it as being 304 or 316.