Nickel alloys are more expensive than stainless steel. However, the comparison of the economy based on the initial cost rather than the life cycle cost may mislead people. For example, the ni-cr-mo alloy is about five times the price of 18cr-8ni stainless steel and twice as much as the super austenitic stainless steel. But as a result of nickel alloy excellent corrosion resistance, the increase of the initial costs are often able to through the extension of equipment life, lower maintenance cost and little downtime caused by long-term cost savings and compensated.
The physical properties of nickel alloy are very similar to that of 300 series austenitic stainless steel. The thermal expansion rate of nickel-base alloy and carbon steel is roughly equal, while the thermal expansion rate of stainless steel is obviously lower than 300.Hoja de acero inoxidable laminado en frío 310S
Although the thermal conductivity of pure nickel is higher than that of carbon steel, the thermal conductivity of most nickel alloys is significantly lower, and in some cases is lower than the thermal conductivity of austenitic stainless steel.Hoja galvanizada galvanizada de alta calidad
In addition to pure nickel, the strength of nickel alloys used in chemical processing is much higher than that of 300 series stainless steel. Nickel alloys also have excellent ductility and toughness (see table 2 for room temperature mechanical properties). For most of the alloy chemical equipment maximum allowable stress see ASME boiler and pressure vessel code first Ⅷ volumes.
Nickel alloy is an all-austenitic microstructure. Almost all of the nickel alloys used in the chemical industry are solid solution. Their intensification comes from the addition of effective hardening elements such as molybdenum and tungsten, rather than the formation of carbides. Like austenitic stainless steel, solid - soluble nickel alloys cannot be strengthened by heat treatment, but only by cold - processing.
Another type of nickel-based alloy can be strengthened by precipitation hardening heat treatment. Most of these alloys are specially designed for ultra high strength applications, such as the alloys used in deep gas production and ultra-high pressure processes.
In addition to valves and rotating machinery parts, the precipitation hardening nickel base alloy has limited application in chemical equipment. These alloys include a gas turbine, a combustion chamber, and a heat-resistant superalloy used for aerospace purposes.Placa gruesa del inspector del acero inoxidable 304 de 6m m