Stainless steel’s resistance to corrosion, strength and relative ease of working make it popular for construction, infrastructure, and interior design. Although elegant and surprisingly robust, it presents a number of challenges to any welder.
It is much more difficult to weld than normal steel and needs professional stainless steel welding with specialist skills. The metal is less ductile, which means the welder needs to consider heating and cooling, while any filler metals need to match the base material as closely as possible.
In this article, we’ll explore:
- Why stainless steel is so popular
- What the metal is used for
- Challenges for welders
- Common stainless steel welding techniques
- How we overcome the challenges
This useful information will help you find specialist stainless steel welding services that will not let you down.
Why use stainless steel?
Globally, the market size of stainless steel was US$ 111.4 billion in 2019 and is expected to witness compounded growth at 6.3% per annum until 2027, on account of rising consumer demand.
Firstly, let’s explore why stainless steel has become so widespread. It is strong enough to use as a building material, yet elegant enough to use as a decorative finish. This metal’s unique properties are due to the chromium added to iron during the steel-making process, which offers resistance to rust.
The amount of chromium in the mix gives slightly different chemical properties and attributes, making it important to use the right grade for a particular task. However, while the properties of stainless steel make it extremely useful, it is expensive and difficult to weld. Despite this, it is found almost everywhere in the home and workplace.
Why is stainless steel so popular across a variety of industries?
The metal’s popularity stems from an almost unique blend of features that ensure it suits many different applications and industries.
Petrochemical Industry
Not only is it particularly resistant to rust, but it is also resistant to attack from various chemicals and gases, and many grades of stainless steel shrug off extreme temperatures. These attributes make it particularly popular with the petrochemical industries.
Architecture and Interior Design
In architecture and interior design, its high-quality finish, low maintenance, and resistance to rust make it a metal of choice for handrails, gates, cladding, countertops, shelving, and other architectural features. Stainless steel’s corrosion resistance and strength make it important for industrial machines and infrastructure.
Energy
In the energy industry, its rust resistance and relative chemical inertness see it used for gas and oil pipelines, while its resistance to saltwater makes it important for oil rigs and renewable energy facilities. The automation, aviation, and rail industries use the metal for exhausts, structural components and tanks used to transport food, petroleum, and chemicals.
Pharmaceutical Production and Food Preparation
Stainless steel is widely used for machines and work surfaces in pharmaceutical production and food preparation areas because of its resistance to bacteria and corrosion, alongside the easy-to-clean finish. These traits also make it useful for cutlery and surgical instruments where sterilisation is particularly important.
Although a very useful material across a variety of industries, it does present some significant challenges to welders.
What are the challenges of welding stainless steel?
Because stainless steel is particularly efficient at retaining heat, it can be a difficult metal to work with, even for experienced welders. Too much heat and the metal can warp. It is also likely to undergo distortion as it cools.
Stainless steel’s beautiful finish also means that every single blemish and scratch mars the surface and is noticeable. Welders have to handle the metal very carefully during preparation, welding, and finishing to protect the surface. Overall, it is not metal for inexperienced welders because even the slightest mistake is visibly apparent.
Fortunately, Sydney Welders’ experts have vast experience in working with stainless steel and take time to make sure they complete the work without causing any damage.
What is the best type of welding for stainless steel?
As with normal carbon steel, MIG, TIG and stick welding are suitable for stainless steel. The right technique to use depends upon the grade of stainless steel, the nature of the task, the thickness of the metal, and the desired quality of finish.
Each of these stainless steel welding techniques delivers different results, which is why special consideration must be first given to the specific priorities of the job to determine the best process.
TIG welding – Finesse and low distortion
TIG welding is perfect in instances where the finish is important as it leaves controlled and neat welds. The process delivers lower heat than others, so there is a lower chance of distortion and warping. However, it is slower than the other techniques and requires a much higher skill level, which only experienced welders possess.
MIG welding – Quick and efficient
MIG welding is faster and more cost-effective than TIG welding. It also requires lower skill levels. However, the final finish may not be as attractive and there is a higher chance of distortion due to the intensity of heat. MIG’s speed and highly portable equipment make it perfect for repair and maintenance work. It can also use a pulsed current that allows the welder to use the head in difficult-to-access areas for particularly complex pieces.
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Importance of preparation
Stainless steel is sensitive to the presence of normal carbon steel. Even the tiniest amount in the weld contaminates the base metal and acts as a focus for rust. In addition, if the welding process removes the chromium oxide layer during heating and cooling, this increases the chances of corrosion.
For this reason, thorough preparation is crucial and surfaces must be kept perfectly clean with the oxide layer preserved. A welder must avoid carbon steel tools, including wire brushes, hammers, cutters, and clamps because they can contaminate the metal. In addition, a welder working on carbon steel should avoid producing dust from grinding and filing near stainless steel.
Filler Material
One other important consideration involves ensuring that the type of filler material used matches the stainless steel type used in the base metal. Sometimes, a welder will have to join or overlay different materials, so they need skill and good judgement to use the most suitable filler material for the job.
The Sydney Welders professionals are fully aware of all of these nuances of stainless steel and follow robust procedures to minimise contamination. We keep stainless steel tools separate, to avoid cross-contamination, and store them away from potential sources of carbon steel dust and particles.
Hire an experienced stainless steel welding expert for your next project in Sydney
Overall, although stainless steel has a desirable finish, durability, and other properties that see it used for many applications. But it can be challenging to weld. Fortunately, our experienced, fully AS1796 certified welders are comfortable working with this metal and selecting the optimal technique. They are also aware of all the relevant health and hygiene standards.
If you want to discuss a stainless steel welding project and find out more about our capabilities, get in touch with Sydney Welders today.