Annealing furnace can help make the metal more ductile, softer, and homogenize the structure of the metal. The annealing furnace can process various types of metals. Some of the metals parts that undergo annealing process include spring assemblies used in automobiles and large blocks of metal that are machined into parts.
A number of factors influence the type of annealing procedure that are required by metals. Some of the factors that determine the annealing procedure required by a metal include:
- Usage of the Metal
- Type of metal: ferrous or non-ferrous
- Reaction of metal to furnace environment
- Treatment effect desired
Here we will focus on how annealing furnace assists in preserving shiny appearance of stainless steel. Stainless steel, also known as chromium alloys, reacts to certain furnace environment. An annealing furnace helps preserve the shiny appearance of the stainless steel.
Annealing Furnace: An Overview
Annealing furnace is a heat-treating furnace maintains an atmosphere of hydrogen or nitrogen. The furnace applies vacuum to eliminate other gases from the heating chamber. The heat furnace is ideal for heating stainless steel that ensures that the metal retains its lustrous shine.
Stainless steel is composed of a chemical element called Chromium. It has a shiny appearance and high melting point. The shiny appearance of the metal is gone if the metal is heated in a furnace that contains oxygen. That’s why it needs to be heated in a special annealing furnace that ensures that the metal retains its shiny appearance.
Preparation for Heating
Before placing the metal in the annealing heat furnace, the stainless steel is cleaned of dirt, coatings, and other residues. These substances oxidize inside the heating chambers that result in loss of shine of the stainless steel. It could also tarnish image of the metal. After cleaning the metal the stainless steel is placed inside the annealing furnace. It is placed directly without any flux. Although, flux help prevent formation of oxide in the metal during heating, but it is not necessary and annealing furnace ensures that oxygen is kept out of the furnace.
The duration of annealing process depends on various factors. The composition of steel and the change required in the metal – such as more ductility, increased hardness, improved substrate – will determine the total time it needs to be placed inside the annealing furnace.
Usually the time the metal is placed at the required temperature is less to avoid grain growth and scaling of the surface. Both of these conditions cause the metal to have an appearance of an orange peel. That’s why the treatment time is set less than 30 minutes. After the treatment duration, the stainless steel metal comes out with a homogenous appearance and maintains its lustrous shine.
