Welding, also known as weld joint, creates a durable, long-lasting bond between the materials by applying heat, pressure, or both. It is an adaptable and famous technique used in many different industries such as repair, manufacturing, and construction. 304 Stainless steel is used in various fields, for instance, industry equipment, food and beverage industry, chemical and others. In the 304 stainless steels, which are a group of iron-based alloys, the wires that are welded indicate a chemically balanced, strong, and base metal-consistent weld joint. Therefore, it is necessary to weld the steel with suitable wire in order to take full advantage of its properties.
In today’s blog, we will learn which is the best wire for welding 304. This type of stainless steel is among many wires and how they work, as well as what benefits the wire will provide to this steel. Let’s begin.
Types of Wires Used in Welding 304 Stainless Steel
304 stainless steel is recognised as the most popular and adaptable form of stainless steel, and they are well known for having great corrosion resistance, weldability and formability. This steel is made up of various materials which help it to stand out from other steel. Materials like iron, chromium, nickel, carbon, manganese and many more are used to enhance its specific properties.
Therefore, to weld 304 stainless steel, different types of wires (filler wire) are used to prevent corrosion issues, improve weld strength, enhance weld quality, and better compatibility. Some of them are as follows:
1. ER347
ER347 is needed when welding 304 stainless steels. Besides this type of stainless steel, 304L, 321, 347 and many other similar alloys can be welded with this wire. In applications where stabilization and higher temperatures are common in challenging environments, this wire is especially useful.
Aerospace, petrochemical, exhaust systems and power generation are among the industries that frequently use ER347 wire. Different components are used in the construction of this wire. The composition is mentioned below:
- Carbon: 0.08%
- Nickel: 9-12%
- Silicon: 0.75%
- Chromium: 17-19%
- Columbium/Niobium: 0.5-0.10%
- Phosphorous: 0.045%
- Manganese: 1.0-1.5%
- Sulfur: 0.03%
With all these combinations of materials, ER347 performs well in high-temperature environments, ensures resistance to oxidation, maintains integrity, offers good weldability and many more.
2. ER316L
ER316L is a type of wire which is used specifically to improve performance in aggressive environments. The L in ER316L wire stands for ‘low-carbon’ which is crucial for maintaining corrosion resistance in elevated temperatures.
ER316L is used in the components which are shown to marine and seawater environments where chloride-induced corrosion is a concern. It is suitable for processing equipment, pharmaceutical industry, oil and gas industry, chemical processing etc.
This wire is made of several elements with distinct compositions. These are as follows:
- Nickel: 10-14%
- Chromium: 16-18%
- Carbon: 0.03%
- Molybdenum: 2-3%
- Sulfur: 0.03%
- Phosphorous: 0.045%
- Manganese: 1.0-1.5%
- Silicon: 0.75%
3. ER308L
ER308L is a wire which is used in welding austenitic 304 stainless steel. It has a minimal carbon content that helps to minimise the risk of intergranular carbide precipitation and cracking that occurs during welding as well as maintaining stability of the weld metal. It ensures compatibility and corrosion resistance.
Applications where this wire is commonly used are repair and maintenance, architecture, construction, beverage and food industry. ER308L is composed of several materials with a composition such as:
- Manganese: 1.0-2.5%
- Nickel: 9.0-11.0%
- Chromium: 19.5-22.0%
- Silicon: 0.30-0.65%
- Carbon: 0.03%
- Copper: 0.75%
- Molybdenum: 0.75%
- Phosphorous: 0.03%
- Sulfur: 0.03%
4. ER308
ER308 wire is similar to ER308L, however the only difference is that it contains slightly higher carbon content. This wire is mainly used where post-weld heat treatment is performed to dissolve carbides. It is best known for its ease of use, mechanical properties and corrosion resistance properties.
ER308 is suitable for pressure-containing and structural properties as it welds with good tensile strength. It also helps to absorb stress and impacts without cracking. This wire is mainly used in general manufacturing, chemical processing, architectural work and many more. It is also composed of different components such as:
- Carbon: 0.08%
- Nickel: 9-12%
- Chromium: 19-21%
- Phosphorous: 0.045%
- Sulfur: 0.03%
- Silicon: 0.75%
- Manganese: 1.5-2.5%
5. ER309L
ER309L is a less carbon wire that is needed to join different grades of steel may be mild steel or low-alloy steel to carbon steel or stainless steel. It has an excellent ability to handle various material compositions and thermal expansion rates.
ER309L is also suitable for handling high-temperature applications. It is also used in many welding processes such as MIG (Metal Inert Gas) and TIG (Tungsten Inert Gas).
This wire is used in a wide range of applications like automotive, aerospace, construction, petrochemical, power generation, industrial equipment, maintenance and repair. The elements which are present in this wire are mentioned below:
- Sulfur: 0.03%
- Phosphorous: 0.045%
- Manganese: 1.5-2.5%
- Silicon: 0.75%
- Carbon: 0.03%
- Nickel: 12-15%
- Chromium: 22-25%
Out of these types of wires, you can choose any of these wires depending on the specific requirements of the application. One of the best and most commonly used filler wire is ER308L wire for 304 stainless steels.
Should you go with ER308L Wire?
Yes, you should go with ER308L wire as it is the best choice for welding 304 stainless steel. This wire is designed specifically to match the composition of this particular steel. It ensures a good match and strong weld integrity in terms of similar chemical composition of nickel and chromium content. The low carbon in ER308L helps to reduce the chance of carbide precipitation during welding which makes it significant. Intergranular corrosion can result from carbide precipitation in the weld’s heat-affected zone. This risk can be minimized by using ER308L wire which will help to keep the weld durable and resistant to corrosion.
ER308L wire mechanical properties can handle the strain and stress without cracking which helps in maintaining the structural integrity of the welded component. Because it produces clean welds, it is simple to use. For projects involving the general fabrication of 304 stainless steel components, like those in the food and beverage industry, chemical processing or architectural applications, ER308L is a great choice. Also, this wire provides a stable and uniform means of maintenance and repairs for 304 stainless steel structures, guaranteeing that the properties of the repaired welds match those of the original material.
Closing Lines
In conclusion, 304 stainless steels can be well-welded with ER308L wire which is designed to match the composition of both the base metal and filler wire. Its carbon content helps to reduce the chance of corrosion and offers good weldability and durable welds to maintain the mechanical properties. ER308L is an ideal choice which provides reliable and high-quality results among various applications ranging from repair to general fabrication.