Stainless Steel

Stainless steel is a steel alloy, and it does not really corrode, rust or stain with water as ordinary steel does. Nonetheless, it is not stainPROOF, just stainLESS! but despite the name it is not fully stain-proof, most notably under low oxygen, high salinity, or poor circulation environments.

Stainless steel differs from carbon steel by the amount of chromium present. Unprotected carbon steel rusts readily when exposed to air and moisture. This iron oxide film (the rust) is active and accelerates corrosion by forming more iron oxide, and due to the greater volume of the iron oxide this tends to flake and fall away. Stainless steels contain sufficient chromium to form a passive film of chromium oxide, which prevents further surface corrosion and blocks corrosion from spreading into the metal's internal structure, and due to the similar size of the steel and oxide ions they bond very strongly and remain attached to the surface.

High oxidation-resistance in air at ambient temperature is normally achieved with additions of a minimum of 13% (by weight) chromium, and up to 26% is used for harsh environments. The chromium forms a passivation layer of chromium(III) oxide (Cr2O3) when exposed to oxygen. The layer is too thin to be visible, and the metal remains lustrous. The layer is impervious to water and air, protecting the metal beneath. Also, this layer quickly reforms when the surface is scratched. This phenomenon is called passivation and is seen in other metals, such as aluminium and titanium.

Types of Steel

At Ancare, we use only 300 series stainless steel - mostly tpye 304, and sometimes type 316, depending on the client's needs. 

300 series stainless is known as austentic steel, as it has been heated to a temperature high enough to change it's crystal structure from ferrite to austenite. It gets really confusing after that. Just trust us. It's good stuff.

Type 304 is the most common type of stainless steel.It can also be referred to as 18/8 (for its composition of 18% chromium and 8% nickel,) or as A2 stainless (not to be confused with A2 grade steel, also named Tool steel.) The second most common austenite steel is Type 316 grade, also called marine grade or surgical stainless, used primarily for its increased resistance to corrosion.

Stainless steel differs from carbon steel by the amount of chromium present. Unprotected carbon steel rusts readily when exposed to air and moisture. This iron oxide film (the rust) is active and accelerates corrosion by forming more iron oxide, and due to the greater volume of the iron oxide this tends to flake and fall away. Stainless steels contain sufficient chromium to form a passive film of chromium oxide, which prevents further surface corrosion and blocks corrosion from spreading into the metal's internal structure, and due to the similar size of the steel and oxide ions they bond very strongly and remain attached to the surface. That's why stainless stains less...

Welding

 

We use 2 types of welding in our processes: Electric Resistance Welding (ERW) and Tungsten Inert Gas (TIG.)

Resistance welding is a technique in which the parts to be joined are held together under pressure and heat is produced by passing a current through the contact resistance formed between the two surfaces. Spot welding is a form of resitance welding, and it is ideal for use when fabricating items such as bottle baskets, wire bar lids, or a wide range of other items.

TIG welding is an arc welding process that uses a non-consumable tungsten electrode to produce the weld. The weld area is protected from surrounding air by Argon, an inert shielding gas.

A constant-current welding power supply produces energy which is conducted across the arc through a column of highly ionized gas and metal vapors known as a plasma. It is a slow process requiring highly skilled workers, but a very high quality weld is achieved.

 

Finishes

 

Standard mill finishes can be applied to flat rolled stainless steel directly by the rollers and by mechanical abrasives. Steel is first rolled to size and thickness and then annealed to change the properties of the final material. Any oxidation that forms on the surface (mill scale) is removed by pickling, and a passivation layer is created on the surface. A final finish can then be applied to achieve the desired aesthetic appearance.

At Ancare, our stainless arrives with a standard 2B mill finish. That means the metal has been cold rolled, annealed, pickled and passivated, then rolled once more on highly polished rollers for a bright, defect free finish.

In order to maintain a high finish, weld marks are removed using a bead blast proceedure. In our specially designed chamber, large items are blasted by glass beads shot out using high pressure air. The final result is a clean, matte finish that is hardened and even more resistant to corrosion.

Smaller items are ideal for electropolishing, a process by which metal is removed from a work piece by passage of electric current while the work is submerged in a specially-designed solution. The process is essentially the reverse of electroplating. In a plating system, metal ions are deposited from the solution onto the work piece; in an electropolishing system, the work piece itself is dissolved, adding metal ions to the solution.

 

Need Something Different? Think Custom...

Since we have our own plant, we can directly address your special needs. We know the industry, and we know our clients. Just tell us what you want, and if it can be done then we are the ones to do it for you! Whether it's something brand new or just tweaking an existing product, we are ready and willing to help you get what you need.