Corrosion Resistant - Stainless Steel Alloys
Castings are classified as “corrosion resistant” if they are used in aqueous environments and vapours below 650°C. To perform well in a corrosive environment the carbon content should be low and usually below 0.20% and sometimes below 0.03%. Based on microstructure Corrosion resistant cast alloys are grouped as Martensitic, Austenitic, or Duplex.
Heat Resistant Alloys
Castings are classified as heat resistant if they are capable of sustained operation while exposed, either continuously or intermittently to operating temperatures that result in material temperatures in excess of 650°C. The application of heat resistant alloys depends on
- Resistance to corrosion at elevated temperature
- Stability - resistance to warping, cracking, thermal fatigue at elevated temperature.
- Creep strength
Alloys for Cryogenic Applications
The austenitic stainless steels and titanium alloys possess a unique combination of properties which makes them useful at cryogenic (very low) temperatures, such as are encountered in plants handling liquefied gases. These materials at cryogenic temperatures have tensile strengths substantially higher than at ambient temperatures while their toughness is only slightly degraded.
Low Magnetic Permeability
Supreme can produce a range of alloys that have low magnetic permeability's of 1.05 Mu or lower. We have the capability to report the magnetic permeability of alloys in accordance with ATSM A342 method 3. Supreme can produce and measure the magnetic permeabiltiy of alloys to lower than 1.01 Mu.
Non Sparking Alloys
Supreme can produce a range of alloys that can be used in environments where fires and explosions are a concern. These include industries where fluids both vapour and liquids, and particulates such as dust and residue are present and can be ignited.
Steel with minimum chromium content of 10.5% is classified as Stainless steel. Stainless steel castings are classified as “corrosion resistant” when used in environments below 650°C and “heat resistant“ when used above 650°C. The main difference between these classifications is carbon content. Stainless steels will have low carbon content to perform well in corrosive environments, and heat resistant grades have higher carbon content to improve elevated temperature strength.
Carbon & Low Alloy Steels
Carbon steels are steels with very few alloying ingredients, primarily only Manganese and Silicon. They are used in many structural applications as provide good strength and are the cheapest steels to produce. Low alloy steels have a wide range of uses due to the increased mechanical properties over that of carbons steels with the addition of alloying ingredients such as Ni, Cr, Mo in relatively low levels. They generally are an excellent balance between mechanical properties and cost.
Tool steel castings are used where hardness and abrasion resistant properties are required. Tool steel is generally divided into three classes; cold work steels, hot work steels, and high speed steels. Cold work steels, are typically used for temperatures below 200° C. These steels have high levels of wear resistance, impact toughness, and hardness. Hot work and high speed steels generally have similar characteristics to cold work steels, but can withstand much higher temperatures before experiencing distortion. Toughness, abrasion resistance, cutting edges, and distortion resistance vary depending on usage temperature and grade of tool steel. Heat treatment such as Annealing, Tempering etc. allows tool steel to achieve various levels of hardness ranges from RC 20 to RC 60.
Supreme can produce high alloy cast irons. These cast irons can be used in varied applications, from corrosion, heat and wear resistance. These irons also are employed when unusual physical properties, such as low thermal expansion or nonmagnetic properties, are desired. Nickel-containing cast irons are used both for corrosion resistance in seawater pumps and for wear resistance in, for example, ore crushing
Non Ferrous Alloys
Aluminium alloys are widely used in engineering structures and components where light weight or corrosion resistance is required. Of the cast aluminium alloys, alloy A-356 has the best overall balance between mechanical properties, cast ability, and corrosion resistance and is the most commonly used aluminium casting alloy for corrosion service
Copper alloy castings are used in applications that require superior corrosion resistance, high thermal or electrical conductivity, good bearing-surface qualities or other special properties.
Nickel & Cobalt Base Alloys
Cobalt and nickel investment castings, also known as superalloys, provide high end corrosion and abrasion resistance at the most extreme temperatures. When it comes to investment casting, Cobalt and nickel share many mechanical properties with stainless steel castings, but are designed for even greater strength and oxidation resistance. These super alloy castings offer unmatched temperature resistance, surface stability under high stress conditions, and overall hardness. Due to their impressive mechanical properties and heat resistance, nickel and cobalt both enjoy long service high resistances to oxidation carburization.