Stainless steel fittings are of fundamental importance to many industries due to certain properties of corrosion-resistance and temperature-resistance not to mention its unmatched strength. Stainless steels resistance to corrosion and staining, low maintenance including its familiar luster makes it an ideal material for different applications from coils, tubing, sheets, plates, bars, fittings and wire used in many different instruments and devices. Due to the fact that steel does not oxidize, stainless steel fittings are widely used in commercial kitchens and food processing plants since it can be steam-cleaned and sterilized without the need for surface finishes or paint. Easy cleaning capabilities make them ideal for hygienic areas where washdowns are commonly done.
Features of stainless steel fittings
- Its properties of self-healing help reduce the penetration of rust/corrosion and eliminate damage to the fitting
- Stainless steel fittings manage to retain its strength whether in extreme heat or extreme cold temperature conditions
- Fittings surface is easy to clean and maintain
- Due to the superior strength and durability of stainless steel fittings, it reduces replacements which lowers the total cost of ownership and increases the returns on investment
- Stainless steel fittings do not need any surface finishes or paint as well as harsh environment-damaging cleaners to make it look like new
- Stainless steel fittings are ideal for industrial MRO and OEM applications in the food and beverage industry, pharmaceuticals, petrochemicals, wastewater and other corrosive environments
Classifications of stainless steel
- Austenitic stainless steel – makes up 70% of total stainless steel production. It contains a maximum of 0.15% carbon, a minimum of 16% chromium and sufficient nickel/manganese to retain its austenitic structure at all temperatures whether extreme cold or extreme heat. The most widely used austenite steel is the 304 which is also known as 18/8 due to its composition of 18% chromium and 8% nickel.
- Ferritic stainless steel – has reduced corrosion resistance due to lower chromium and nickel content; however, they have better engineering properties than austenitic steel and considered to be less expensive. They contain between 10.5% to 27% chromium and very little nickel.
- Martensitic steel – not so high corrosion resistance if compared to austenitic and ferrous stainless steel but extremely strong and tough, highly machinable and can be hardened using heat treatment. Martensitic steel contains 12-14% chromium, 0.2-1% molybdenum, less than 2% nickel and about 0.1-1% carbon. Its carbon content makes it harder but a bit more brittle.
- Duplex stainless steel – a 40/60 combination of both austenitic and ferritic stainless steels to achieve twice the strength of austenitic stainless steel and improved resistance to localized corrosion particularly pitting, crevice corrosion and stress corrosion cracking.
- Precipitation-hardening martensitic stainless steel – has corrosion resistance comparable to austenitic stainless steel but can be precipitation hardened to reach higher strengths comparable to the martensitic grades.
It is always important to focus a lot of attention on the alloying elements used in stainless steel fittings to avoid corrosion. It is also extremely important to avoid dropping below the minimum chrome threshold so as to guarantee the specific properties of the stainless steel fittings.
