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STAINLESS STEEL WHAT IS STAINLESS STEEL? Stainless steel is essentially a low carbon steel which contains chromium at 10% or more by weight. It is this addition of chromium that gives the steel its unique stainless, corrosion resisting properties. The chromium content of the steel allows the formation of a tough, adherent, invisible, corrosion-resisting chromium oxide film on the steel surface. If damaged mechanical1y or chemically, this fi1m is self-healing, provided that oxygen, even in very small amounts, is present. The corrosion resistance and other useful properties of the steel are enhanced by increased chromium content and the addition of other elements such as molybdenum, nickel and nitrogen. WHY STAINLESS STEEL? The many unique values provided by stainless steel make it a powerful candidate in materials selection. Engineers, specifies and designers often underestimate or overlook these values because of what is viewed as the higher initial cost of’ stainless steel. However over the total life of a project; stainless is often the best value option. USEFUL FACTS ABOUT STAINLESS STEELS & BENEFITS OF STAINLESS STEEL CONDITIONS WHICH FAVOR USE OF STAINLESS STEEL Corrosion resistance – can withstand Corrosive Environment, therefore Environment friendly --- lower alloyed grades resist corrosion in atmospheric and pure water environments, while high-alloyed grades can resist corrosion in most acids, alkaline solutions, and chlorine bearing environments, properties which are utilized in process plants. Corrosion resistance means no painting and durability for decades – no thinning, no corrosion allowance . Fire & heat resistance ---special high chromium and nickel-alloyed grades resist scaling and retain strength at high temperatures Hygiene — therefore easy clean ability --- the easy cleaning ability of stainless makes it the first choice for strict hygiene conditions, such as hospitals, kitchens, abattoirs and other food processing plants. No contamination, prevents catalytic reactions. Easy cleanability means minimal maintenance, especially in inaccessible areas Aesthetic appearance --- No rust, therefore no paint necessary ---the bright, easily maintained surface of stainless steel provides a modern and attractive appearance. High Strength -to- Weight (Mass) Advantage ----the work-hardening property of austenitic grades, that results in a significant strengthening of the material from cold- working alone, and the high strength duplex grades, allow reduced material thickness over conventional grades, therefore cost savings. Ease of fabrication ---modern steel-making techniques mean that stainless can be cut, welded, formed, machined, and fabricated as readily as traditional steels. Impact resistance & Abrasion resistance ---the austenitic microstructure of the 300 series provides high toughness, from elevated temperatures to far below freezing, making these steels particularly suited to cryogenic applications (at very low temperatures it resist brittleness). Withstands erosion. Absorbs 2.5 times the energy of carbon steel during deformation. Non – magnetismin case of Austenetic ---helps escape detection Long term value ---when the total life cycle costs are considered, stainless is often the least expensive material option. CLEANING YOUR INDOOR STAINLESS STEEL Retaining a sparkling finish on stainless steel surfaces is just a matter of a few simple steps. And you don’t need expensive products or special equipment — ordinary household cleaners are usually all that’s required. You just need to bear in mind a few easy DOs and DON’Ts It’ll come out in the wash Stainless steel looks best if it’s cleaned regularly with plenty of water. Drying afterwards makes sure streaky marks aren’t left behind. Remember that simply wiping with a damp cloth is not as effective as it can smear dirt without removing it. Routine cleaning prevents any stubborn stains building up. So what will you need? You don’t need any fancy equipment. For day to day cleaning, plenty of water, some mild detergent and a cloth or soft brush will do the job. You can use a 1% ammonia solution but don’t use bleach — it’s just too easy to make the solution too strong and too hard to rinse it properly afterwards. After washing, rinse in clean water and wipe the surface dry with a soft absorbent cloth. On brushed stainless steel, follow the direction of the polish for best results. An excellent cloth to use is 3M’s Scotch- Brite high performance cleaning cloth. Watch out for scratches! The important thing to remember is that stainless steel can be scratched by careless handling or aggressive scrubbing. Just like you would take care of a polished timber finish, avoid dragging rough items across the surface and be aware that grit trapped under other objects can be the culprit. Avoid bad chemistry Stainless steel may discolor if left in contact with salts or acids for extended periods. Also avoid leaving carbon steel items in contact with stainless steel, particularly if wet. But if you observe ordinary hygiene measures, like timely cleaning-up in food preparation areas, you won’t have any problems. Don’t go against the grain Always rub stainless steel in the same direction as the grain. Rubbing against the grain will spoil the finish and stainless will lose its shine. Worse, rubbing against the grain can damage the surface by creating microscopic crevices where dirt can collect. This can lead to corrosion spots. Fortunately, it’s usually easy to tell which the right direction is. You need to watch out for items like round handrails, which are often polished around their circumference when they’re manufactured, rather than up and down the length of the tube. If you have to scrub a stain to remove it, make sure you use a clean nylon scourer or a cloth with chalk-based cream cleaner. But test an inconspicuous area first as you could end up with a bright polished spot which doesn’t match the rest of the surface. NEVER EVER use steel wool (wire wool) to clean stainless steel. It is usually made of carbon steel and any fragments left behind will rust onto the stainless steel surface. Using any kind of scourer which has previously been used on ordinary (carbon) steel is also a no-no for the same reason. Stainless steel wool scouring pads are available for heavy duty work, like removing burnt food from stainless steel saucepans. These will scratch the stainless steel surface, but won’t leave fragments to go rusty. Don’t even think about - • Rubbing with steel wool (wire wool) or scraping with steel tools • Using scourers and cleaning cloths that have been used on ordinary steel • Rubbing plastic scourers across the grain of brushed surfaces •Using concentrated bleach or hydrochloric acid-based cleaning products CLEANING. Nitric Acid (HNO3) - Nitric acid is a “friendly” acid towards Stainless Steel and is the only mineral acid which should be used to clean stainless steel. Avoid contact of the acid with other metals, particularly the aluminium and copper bases on cookware. A 10% solution (1 part Nitric Acid added to 9 parts water) is usually used. It may be obtained from most chemists. who will make up the 10% solution. Concentrated Nitric Acid must be handled with care. Dilute 10% solutions are less dangerous, but it is advisable to wear rubber gloves and eye protection. If accidental skin contact occurs, wash well with lots of water. Mix and keep the solution in glass containers. Dilute extensively before flushing down the drain. Keep it out of reach of children. TIPS Rust marks Apply cream cleanser with a soft damp cloth and rub gently. If the mark still won’t shift, it might be necessary to use a proprietary stainless steel cleaner. These are usually based on dangerous chemicals (such as phosphoric, oxalic or sulphamic acids) and must be handled with care according to the manufacturer’s directions. After cleaning it is important to neutralize the acid with a 1% ammonia or baking powder solution, rinse with clean water and wipe dry. If the rust has worn away the surface, don’t despair! Bad rusting can be repaired with professional polishing but you will need to get expert advice. Rust spots with a halo around them indicate that a fragment of ordinary steel has become embedded in the surface of the Stainless Steel. Dab and spot. keeping moist for 20 - 30 minutes. with a 10% solution of Nitric Acid on an ear bud. Repeat this treatment until no reoccurrence of the rust spot occurs. Severe rust stains are best removed by swabbing the slain, keeping it moist for 15 - 20 minutes with a 10% solution of Nitric Acid, repeating if necessary. Very severe stains will require hard rubbing with a paste of line household abrasive and 10% Nitric Acid, using a fairly coarse nylon scouring pad, Acid treatments must be followed by rinsing in ammonia or soda bicarb solution, and Routine Cleaning. Sterilization - Add the sterilizing solution in the strength as laid down in the instructions. Avoid ovcrdosing or the addition of concentrated solutions in one large dosage. Do not leave the sterilizing solution in the equipment longer than necessary. especially under stagnant conditions.

STAINLESS STEEL

WHAT IS STAINLESS STEEL?

Stainless steel is essentially a low carbon steel which contains chromium at 10% or more by weight. It is this addition of chromium that gives the steel its unique stainless, corrosion resisting properties.

The chromium content of the steel allows the formation of a tough, adherent, invisible, corrosion-resisting chromium oxide film on the steel surface. If damaged mechanical1y or chemically, this fi1m is self-healing, provided that oxygen, even in very small amounts, is present. The corrosion resistance and other useful properties of the steel are enhanced by increased chromium content and the addition of other elements such as molybdenum, nickel and nitrogen.

WHY STAINLESS STEEL?

The many unique values provided by stainless steel make it a powerful candidate in materials selection. Engineers, specifies and designers often underestimate or overlook these values because of what is viewed as the higher initial cost of’ stainless steel. However over the total life of a project; stainless is often the best value option.

USEFUL FACTS ABOUT STAINLESS STEELS & BENEFITS OF STAINLESS STEEL

CONDITIONS WHICH FAVOR USE OF STAINLESS STEEL

Corrosion resistance – can withstand Corrosive Environment, therefore Environment friendly --- lower alloyed grades resist corrosion in atmospheric and pure water environments, while high-alloyed grades can resist corrosion in most acids, alkaline solutions, and chlorine bearing environments, properties which are utilized in process plants. Corrosion resistance means no painting and durability for decades – no thinning, no corrosion allowance .

Fire & heat resistance

---special high chromium and nickel-alloyed grades resist scaling and retain strength at high temperatures

Hygiene — therefore easy clean ability
--- the easy cleaning ability of stainless makes it the first choice for strict hygiene conditions, such as hospitals, kitchens, abattoirs and other food processing plants. No contamination, prevents catalytic reactions. Easy cleanability means minimal maintenance, especially in inaccessible areas

Aesthetic appearance --- No rust, therefore no paint necessary
---the bright, easily maintained surface of stainless steel provides a modern and attractive appearance.

High Strength -to- Weight (Mass) Advantage
----the work-hardening property of austenitic grades, that results in a significant strengthening of the material from cold- working alone, and the high strength duplex grades, allow reduced material thickness over conventional grades, therefore cost savings.

Ease of fabrication
---modern steel-making techniques mean that stainless can be cut, welded, formed, machined, and fabricated as readily as traditional steels.

Impact resistance & Abrasion resistance
---the austenitic microstructure of the 300 series provides high toughness, from elevated temperatures to far below freezing, making these steels particularly suited to cryogenic applications (at very low temperatures it resist brittleness). Withstands erosion. Absorbs 2.5 times the energy of carbon steel during deformation.

Non – magnetismin case of Austenetic
---helps escape detection

Long term value
---when the total life cycle costs are considered, stainless is often the least expensive material option.

CLEANING YOUR INDOOR STAINLESS STEEL

Retaining a sparkling finish on stainless steel surfaces is just a matter of a few simple steps. And you don’t need expensive products or special equipment — ordinary household cleaners are usually all that’s required.

You just need to bear in mind a few easy DOs and DON’Ts

It’ll come out in the wash
Stainless steel looks best if it’s cleaned regularly with plenty of water. Drying afterwards makes sure streaky marks aren’t left behind.

Remember that simply wiping with a damp cloth is not as effective as it can smear dirt without removing it.

Routine cleaning prevents any stubborn stains building up.

So what will you need?
You don’t need any fancy equipment. For day to day cleaning, plenty of water, some mild detergent and a cloth or soft brush will do the job. You can use a 1% ammonia solution but don’t use bleach — it’s just too easy to make the solution too strong and too hard to rinse it properly afterwards.

After washing, rinse in clean water and wipe the surface dry with a soft absorbent cloth. On brushed stainless steel, follow the direction of the polish for best results. An excellent cloth to use is 3M’s Scotch- Brite high performance cleaning cloth.

Watch out for scratches!
The important thing to remember is that stainless steel can be scratched by careless handling or aggressive scrubbing. Just like you would take care of a polished timber finish, avoid dragging rough items across the surface and be aware that grit trapped under other objects can be the culprit.

Avoid bad chemistry
Stainless steel may discolor if left in contact with salts or acids for extended periods. Also avoid leaving carbon steel items in contact with stainless steel, particularly if wet. But if you observe ordinary hygiene measures, like timely cleaning-up in food preparation areas, you won’t have any problems.

Don’t go against the grain
Always rub stainless steel in the same direction as the grain. Rubbing against the grain will spoil the finish and stainless will lose its shine. Worse, rubbing against the grain can damage the surface by creating microscopic crevices where dirt can collect. This can lead to corrosion spots.

Fortunately, it’s usually easy to tell which the right direction is. You need to watch out for items like round handrails, which are often polished around their circumference when they’re manufactured, rather than up and down the length of the tube.
If you have to scrub a stain to remove it, make sure you use a clean nylon scourer or a cloth with chalk-based cream cleaner. But test an inconspicuous area first as you could end up with a bright polished spot which doesn’t match the rest of the surface.
NEVER EVER use steel wool (wire wool) to clean stainless steel. It is usually made of carbon steel and any fragments left behind will rust onto the stainless steel surface. Using any kind of scourer which has previously been used on ordinary (carbon) steel is also a no-no for the same reason.
Stainless steel wool scouring pads are available for heavy duty work, like removing burnt food from stainless steel saucepans. These will scratch the stainless steel surface, but won’t leave fragments to go rusty.

Don’t even think about -

• Rubbing with steel wool (wire wool) or scraping with steel tools
• Using scourers and cleaning cloths that have been used on ordinary steel
• Rubbing plastic scourers across the grain of brushed surfaces
•Using concentrated bleach or hydrochloric acid-based cleaning products

CLEANING.
Nitric Acid (HNO3) - Nitric acid is a “friendly” acid towards Stainless Steel and is the only mineral acid which should be used to clean stainless steel. Avoid contact of the acid with other metals, particularly the aluminium and copper bases on cookware. A 10% solution (1 part Nitric Acid added to 9 parts water) is usually used. It may be obtained from most chemists. who will make up the 10% solution. Concentrated Nitric Acid must be handled with care. Dilute 10% solutions are less dangerous, but it is advisable to wear rubber gloves and eye protection. If accidental skin contact occurs, wash well with lots of water. Mix and keep the solution in glass containers. Dilute extensively before flushing down the drain. Keep it out of reach of children.

TIPS
Rust marks
Apply cream cleanser with a soft damp cloth and rub gently. If the mark still won’t shift, it might be necessary to use a proprietary stainless steel cleaner. These are usually based on dangerous chemicals (such as phosphoric, oxalic or sulphamic acids) and must be handled with care according to the manufacturer’s directions. After cleaning it is important to neutralize the acid with a 1% ammonia or baking powder solution, rinse with clean water and wipe dry. If the rust has worn away the surface, don’t despair! Bad rusting can be repaired with professional polishing but you will need to get expert advice.

Rust spots with a halo around them indicate that a fragment of ordinary steel has become embedded in the surface of the Stainless Steel. Dab and spot. keeping moist for 20 - 30 minutes. with a 10% solution of Nitric Acid on an ear bud. Repeat this treatment until no reoccurrence of the rust spot occurs. Severe rust stains are best removed by swabbing the slain, keeping it moist for 15 - 20 minutes with a 10% solution of Nitric Acid, repeating if necessary. Very severe stains will require hard rubbing with a paste of line household abrasive and 10% Nitric Acid, using a fairly coarse nylon scouring pad, Acid treatments must be followed by rinsing in ammonia or soda bicarb solution, and Routine Cleaning.
Sterilization - Add the sterilizing solution in the strength as laid down in the instructions. Avoid ovcrdosing or the addition of concentrated solutions in one large dosage. Do not leave the sterilizing solution in the equipment longer than necessary. especially under stagnant conditions.