Annealing is the process of changing a metal’s properties to relieve internal pressures, improve cold working properties, and cause ductility and softness.
It’s also applied to existing ones that have hardness and reduced tensile strength because of use. Metal treating companies provide several services for stainless steel annealing, with bright annealing, stress relief, normalizing, and tempering being widely used for various stainless steel alloys.
Below is a summary of each procedure:
Bright annealing is done to improve ductility and eliminate stress while maintaining the surface quality of stainless steel. To maintain surface quality, it’s done in a vacuum cleaner or constant furnace which features atmosphere control, which offers an oxygen-free air that prevents oxidization.
The procedure increases ductility and eliminates pressures by heating stainless steel, and then slowly cooling it. Since it reduces the brittleness of metal, it’s often applied to bits that need exceptional cold working properties. Get the latest info on 304 vs 316 Stainless Steel (which is also known as “304 เทียบกับเหล็กสแตนเลส 316” in the Thai language) via visiting online websites.
As its name suggests, stress relief relieves anxiety that reduces a metal’s cold working properties and tensile strength. Stress relief is typically applied to metal that’s been formed, machined, flame cut, weld fabricated, or cold worked. Low-temperature stress relief, which reduces stress without compromising corrosion resistance or mechanical properties, is the most common way of stress relief for stainless steel.
Normalizing enhances the mechanical properties of stainless steel by optimizing its crystal structure. This occurs by heating the steel to a temperature that’s slightly above its upper critical point, briefly soaking it in water, and then letting it cool in open air.
Normalizing is typically performed on ferritic stainless steel, often as a precursor to rust. Becoming hard to harden, ferritic stainless steel has a much better response to hardening when it’s normalized before being hardened.
Tempering relieves pressures that result from quenching, and may also reduce hardness. It’s often implemented after the metal has undergone quench annealing – a process which cools steel from 1900 degrees Fahrenheit to under 900 degrees Fahrenheit almost instantly, which prevents carbide formation across the grain boundaries.