Austenitic, Martensitic, Ferritic, Precipitation Hardened. SS 303, SS 304, SS 316, SS 410, SS 416, SS 420, SS 440, SS 17-4PH, SS 17-7PH Though the terms Stainless it is misnomer in many practical conditions. Most stainless steel varieties are susceptible for corrosion in certain processes or atmospheres.
Cobalt Chrome Alloy ( CoCr ) Corrosion Passivation / Pickling / Treatment Chemicals
These alloys due to its corrosion resistance used in implant industry. However there is scope for passivation in many process related applications.
Nickel Cobalt Alloy ( NiCo ) - Superalloys Corrosion Passivation / Pickling / Treatment Chemicals
Nickel & cobalt-based alloys and superalloys are used in jet engines, gas turbines, chemical processing, petroleum refining, marine, electronics and other applications where common stainless steels may not provide adequate performance. Corrosion inhibition though suitable process is essential to guard surfaces.
Nickel Alloys ( Ni ) Inconel, Monel, Hastelloy, Nitinol Alloy Corrosion Passivation / Pickling / Treatment Chemicals
Inconel : It is often encountered in extreme environments.
It is common in gas turbine blades, seals, and combustors, as well as turbocharger rotors and seals,
electric submersible well pump motor shafts, high temperature fasteners, chemical processing and pressure vessels, heat exchanger tubing, steam generators and core components in nuclear pressurized water reactors, It is also used in natural gas processing with contaminants such as H2S and CO2.
Passivation complements its all mechanical and chemical properties and give durable protection.
Monel : It is used in piping systems, pump shafts, seawater valves, trolling wire, and strainer baskets Monel alloys are resistant to corrosion by many agents, including rapidly flowing seawater. They can be fabricated readily by hot- and cold-working, machining, and welding. However the passivation processes Conduct the corrosion inhibition with oxide layers.
Hastelloy : Many nickel-based steel alloys exhibit high resistance to corrosion, and Hastelloy is one of the best. In addition to outstanding resistance to all manner of pitting and cracking, parts made from Hastelloy metal blends tend to find good use across a wide range of chemical applications that might otherwise oxidize the metal. Additional elements such as molybdenum and chromium round out the profile of an alloy that is widely regarded as one of the world’s toughest. The Passivation ensures guard from secondary corrosions and process stress susceptibilities.
NITINOL : Nitinol alloys exhibit two closely related and unique properties i.e. shape memory and superelasticity. Superelasticity occurs at a narrow temperature range just above its transformation temperature; in this case, no heating is necessary to cause the undeformed shape to recover, and the material exhibits enormous elasticity, some 10-30 times that of ordinary metal. This has ability to absorb stresses. Thus the passivation ensures the surface properties remain unaltered during elastic behaviors.