IS STAINLESS STEEL EVEN GRADED?
It’s graded accordance to its chemical makeup, and hence its differing properties. As one steel will probably be more appropriate than another for a particular goal, it is necessary to understand the kinds available. Generally, while stainless steel can withstand many types of corrosion, all grade types will probably be corroded by chlorides, with certain grades which are full of nickel, molybdenum and chromium currently seem to have the most resistance. As well as some steel being completely nonmagnetic, other kinds retain their magnetic attraction.
200 series stainless steel made up of about 17% chromium, 4% nickel and 7% manganese, and is non magnetic. Less common compared to the 300 series level, to which it’s similar, it’s most frequently used for cooking utensils and knives. It retains durability and is less prone to attack compared to 300 series from corrosion. Yet, it frequently breaks down quickly once corrosion has started. It cannot do so forever, with some corrosion starting within months while it can withstand immersion in environments like seawater.
Due to the fact that it is available for use across a variety of areas, including building and national buildings of trains, airplanes and cars. If used in surroundings it is very adept at resisting corrosion, but optimum operation will quickly decrease, where chloride levels are high.
PROPERTIES AND USES OF 400 SERIES
Comprising about 11% chromium and 1% manganese, this kind of series reacts to hardening through heat nicely, but has poor resistance towards corrosion. Unless shielded, 400 series become impractical for almost any seawater use. It’s mostly used in programs which need heat resistance, like exhaust pipes, heat exchangers, combustion burners. As its durability falls quickly in this scenario, it must not be utilized in low temperature surroundings.
PROPERTIES AND USES OF 600 SERIES
In addition, this fact, it retains its magnetism. Exposed to chloride surroundings, 600 series vulnerability increases if exposed to stress cracking when corroded. Most 600 series can only manage to stay without corrosion for a day or two in seawater.
LOGIC MANUFACTURE USING STAINLESS STEEL
Below are just a few street furniture items made from stainless steel in coastal areas – Using Stainless Steel Grade 316.
Grade 316 has to be used on these areas due to the corrosion from the surrounding sea elements,
MANCHESTER SEAT IN LIVERPOOL
SNOWDON BENCH IN SWANSEA BAY CAMPUS
STAINLESS STEEL GRADE 304
What should the first grade be? Not surprisingly, 304 (1.4301) and its variants are the most common grades in the SSAS database. This reflects the market as a whole.
Approximate Composition – 18% Cr 8% Ni (exact composition ranges vary between EN and ASTM standards).
This grade combines the following characteristics:
- Good corrosion resistance
- Good weldability
- Excellent ductility giving stretch formability in pressings
- Hygienic surfaces
- Work hardening for spring properties
- Ease of manufacture at the steel mill
This combination of properties leads to the grade being used for a wide range of applications including:
Sinks, pots and pans, catering surfaces, architectural cladding, handrails, food processing, water treatment, pressure vessels, transport containers, surgical instruments, building support products, refrigeration equipment, watch cases, automotive trim, street furniture, anaerobic digestion, chemical plant, sanitaryware.
This is merely a sample of the applications for 304/304L (1.4301/1.4307). Despite the competition from grades with a similar corrosion resistance, this grade is likely to continue to form the backbone of the stainless steel market for some years to come.
STAINLESS STEEL GRADE 316
Grade 316 (1.4401) is the second in this series of articles about stainless steel grades. It is the most common grade which highlights the benefits of molybdenum (Mo).
Approximate Composition – 17% Cr 10% Ni 2% Mo (exact composition ranges vary between EN and ASTM standards).
Mo enhances the corrosion resistance of stainless steel even in relatively small amounts. 1% of Mo is worth about 3% of Cr in terms of corrosion resistance.
In environments where 304 (1.4301) is found to be inadequate, 316 (1.4401) is the natural first grade to be considered. Typical environments where 316 (1.4401) is used are high chloride (saline, coastal), heavy urban, acidic, high temperature solutions. Like all austenitic stainless steels, 316 (1.4401) has good welding and forming characteristics.
Typical applications which demonstrate the improved corrosion resistance of 316(1.4401) include:
Pharmaceutical plant, chemical processing, offshore oil and gas platform topside equipment, architectural applications in urban and coastal conditions, food processing, water treatment, pressure vessels, transport containers, swimming pool fittings and fixtures, marine structures, yacht fittings, laboratory equipment, heat exchangers.
316 (1.4401) will continue to be an important grade of stainless steel in the more demanding applications for many years to come
STAINLESS STEEL GRADE 430
Grade 430 (1.4016) is the most common ferritic stainless steel grade in sheet form. It features in many familiar everyday items.
Approximate Composition – 17% Cr (exact composition ranges vary between EN and ASTM standards).
This grade combines the following characteristics:
• Fair corrosion resistance
• Fair weldability (in thin sections)
• Excellent deep drawing properties
• Cost effectiveness due to absence of nickel
• Hygienic surfaces
• Thermal expansion comparable to carbon steel
Indoor conditions are usually compatible with the use of 430 (1.4016). Mild chemicals such as detergents and cleaning fluids are safe to use with this grade.
Typical applications include:
Washing machine drums, cutlery, kitchen utensils, catering equipment, microwave oven liners, kick plates, lifts, induction heated pots and pans, cooker hobs, air extraction units, automotive trim, hose clamps, window hinges.
430 (1.4016) is a cost-effective material in many mild environments and will continue to be so for many years.