Introduction

Stainless steel is defined as a steel alloy with a minimum of 10% chromium content by mass. Stainless steel does not stain, corrode, or rust as easily as ordinary steel, but it is not stain-proof. It is also called corrosion-resistant steel or CRES when the alloy type and grade are not detailed, particularly in the aviation industry. There are different grades and surface finishes of stainless steel to suit the environment to which the material will be subjected in its lifetime.

Properties

High oxidation-resistance in air at ambient temperature are 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. It 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. Corrosion resistance can however be adversely affected if the component is used in a non-oxygenated environment, a typical example being underwater keel-bolts buried in timber.

Applications

Stainless steel’s resistance to corrosion and staining, low maintenance, relatively low cost, and familiar luster make it an ideal base material for a host of commercial applications. There are over 150 grades of stainless steel, of which fifteen are most common. The alloy is milled into coils, sheets, plates, bars, wire, and tubing to be used in cookware, cutlery, hardware, surgical instruments, major appliances, industrial equipment, and as an automotive and aerospace structural alloy and construction material in large buildings. Orange juice and other food transport and storage tankers are often made of stainless steel, due to its corrosion resistance and antibacterial properties. This also influences its use in commercial catering kitchens and food processing plants, as it can be steam cleaned, sterilized, and does not need painting or application of other surface finishes.

Chemical Properties

There are different types of stainless steels: when nickel is added, for instance, the austenite structure of iron is stabilized. This crystal structure makes such steels non-magnetic and less brittle at low temperatures. For greater hardness and strength, carbon is added. When subjected to adequate heat treatment, these steels are used as razor blades, cutlery, tools, etc.

Significant quantities of manganese have been used in many stainless steel compositions. Manganese preserves an austenitic structure in the steel as does nickel, but at a lower cost.

300 Series Austenitic Table

400 Series Austenitic Table

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 (scale) is removed by pickling, and the passivation layer is created on the surface. A final finish can then be applied to achieve the desired aesthetic appearance.

• No. 0 - Hot rolled, annealed, thicker plates
• No. 1 - Hot rolled, annealed and passivated
• No. 2D - Cold rolled, annealed, pickled and passivated
• No. 2B - Same as above with additional pass-through highly polished rollers
• No. 2BA - Bright annealed (BA or 2R) same as above then Bright annealed under Oxygen-free atmospheric conditions
• No. 3 - Coarse abrasive finish applied mechanically
• No. 4 - Brushed finish
• No. 5 - Satin finish
• No. 6 - Matte finish
• No. 7 - Reflective finish
• No. 8 - Mirror finish
• No. 9 - Bead blast finish
• No. 10 - heat colored finish-wide range of electropolished & heat colored surfaces

Waterjet cutting

The Water Jet machine produces part shapes by cutting sheet material using a high pressure stream of water containing abrasive particles. CNC Waterjet cutting can create thin details and almost any shape. As there is no heat generated during waterjet cutting, the part being cut does not undergo distortion. High cutting accuracy is achieved without frayed edges or burrs. Therefore, edge quality is good and the need for secondary finishing processes is usually eliminated. Waterjet is considered a "green" technology. Waterjets produce no hazardous waste, reducing waste disposal costs. They can cut off large pieces of reusable scrap material that might have been lost using traditional cutting methods. Parts can be closely nested to maximize material use, and the waterjet saves material by creating very little kerf. Waste water usually is clean enough to filter and dispose of down a drain. The garnet abrasive is a non-toxic natural substance that can be recycled for repeated use. Garnet usually can be disposed of in a landfill.

Cut virtually any material

Because waterjets cut using water and abrasive, they can work with a wide variety of materials. These materials include:

• Copper, brass, aluminum:
• Pre-hardened steel
• Mild steel
• Exotic materialss such as titanium, Inconel and Hastalloy
• 304 stainless
• steel
• Brittle materials such as glass, ceramic, quartz, stone.
• Laminated material
• Flammable materials

Advantages

• Fast setup and programming
• Little fixturing for most parts
• Almost no heat generated on your part
• No mechanical stresses
• Machine thick material
• Are very safe
• Modern systems are now very easy to learn
• Environmentally friendly
• No start hole required
• Narrow kerf removes only a small amount of material

Specification

• Cutting Length: 2.5 mts. (X axis)
• Cutting Width: 1.5 mts (Y axis)
• Maximum lift: 250 mm (Z axis)
• Maximum workpiece thickness: 150 mm

CNC EDM WIRE CUTTING

EDM wire cutting is a cutting process which uses a spark erosion wire to perform 'non-contact' cuts in metal parts. This process uses an electrical discharge that forms an arc between an EDM wire and a work piece to erode or remove metal in its path. EDM wirecutting is commonly used by toolmakers to cut metal inserts or punch tools. Because EDM wirecutting apples no cutting forces to the workpiece and applies little or no heat it can be used to cut very intricate, finely detailed parts in thin metals.

Work Envelope:

Width – X – axis: 300 mm
Length – Y – axis: 400 mm
Height – Z - axis: 300 mm

FABRICATION

We have extensive sheet metal fabrication facilities in-house to cater to your varied demands and requirements. Prototyping as well as large batch production or even long term production is easily catered for.

Industries Served

• Military
• Aerospace
• Oil Companies
• Railways
• Optical Instruments
• OEM Manufacturing

Material handled

• Stainless steel – Train components, Naval parts, Architectural parts, cladding, frame works in 202, 304, 316 grades.
• Mild Steel – Various light and heavy fabrications covering a multitude of applications.
• Aluminium  – Scientific, military, aerospace requirements.
• Brass, Copper etc.

MACHINING

We are committed to deliver the highest quality turned machined parts. We have in-house facilities for basic precision turning and milling in-house whereas we can provide facilities of CNC turning and milling also.

Industries Served

• Military
• Aerospace
• Oil Companies (Thermowells)
• Railways
• Optical Instruments
• OEM Manufacturing

Materials handled

• Aluminum
• Brass
• Copper
• Exotic Materials
• Nylon
• Teflon
• Stainless Steel
• Steel
• Titanium

Welding

We can boast of EN-287 certified welders turning out precise and the highest quality of welds on various metals like: Steel, Aluminium, Stainless Steel (202, 304, 316) etc. with thicknesses upto 12mm. We are equipped with the latest in welding machines and have a Fronius MagicWave 220 welding machine to achieve the same.

Finishing

We have all major in-house finishing facilities to ensure swift completion of the manufactured products without compromise on the finish quality. Finishing equipment include:

• Powder coating plant
• Vibratory Deburring machines
• Buffing
• Brush Finishing
• Passivation
• Zn plating