The Magnetic and Annealing Features of Stainless Steel
316 stainless steel tube suppliers offer high-quality grades at an affordable price to buy.
Magnetism is one of the key features that you will have to consider before purchasing from the 316 Stainless steel tube suppliers. To find out whether the 316 stainless steel tube is magnetic or not maybe be a bit hard.
Some people firmly believe that a stainless steel tube is a nonmagnetic material. Others believe that it is a magnetic material because it has some iron. It is, however, essential to note that stainless steel is somewhere in between.
Factors That Make Stainless Steel Magnetic
For stainless steel to be magnetic, it has to have two properties. First, it must have iron in it. Iron is one of the chemical composition of the steel. Iron has magnetic properties. As such, stainless steel that has iron becomes magnetic.
The second property that makes stainless steel magnetic is the arrangement of the crystal structure. Stainless steel that has a crystal structure arranged in a ferritic or martensitic nature has some magnetic properties. If the crystal structure is arranged in an austenite manner, then it will not have magnetic properties.
Types of Stainless Steel That Are Magnetic
Three types of stainless steel are magnetic. These three are discussed below. The austenitic stainless steel, which is stainless steel that has nonmagnetic properties is also considered:
Ferritic Stainless Steel
Ferritic stainless steels have a substantial quantity of ferrite in their structure. That makes them magnetic. Ferrite is one of the compounds of iron and other elements that have magnetic characteristics. The crystal structure of ferritic combined with iron gives ferritic stainless-steel magnetic properties. However, not all types of ferritic steels have strong magnetic properties. Some have weaker magnetic properties than carbon steel.
Martensitic Stainless Steel
Most martensitic stainless steel has magnetic properties. This is because martensitic steels have a unique crystal structure. In the presence of iron, the martensitic steel becomes ferromagnetic. Iron is a ubiquitous property of steel. This feature gives martensitic steel magnetic properties.
Duplex Stainless Steel
Duplex stainless steel contains a mixture of austenite and ferrite, which gives them magnetic properties. The ferrite substance that duplex steel has is what gives it magnetic properties. However, the presence of austenite in duplex stainless steel makes it less magnetic. This is because austenite has nonmagnetic features.
Austenitic Stainless Steel
The high amount of austenite present in austenitic steel is what gives it nonmagnetic features. Grade 304 stainless steel and grade 316 stainless steel have very high amounts of iron. However, the presence of austenite makes them non-ferromagnetic. This does not apply to when the crystal structure of austenitic steel is changed through thermal treatments and other types of work-hardenings. When this happens, the ferrite may form in some places of the steel giving it partial magnetic properties.
Why Magnetism Matters?
Magnetic features really matter in stainless steel. These features might have a very massive influence on the general performance of stainless steel. For instance, if a material is to be urgently sorted from other materials, then having one magnetic material can easily facilitate this process. Electric currents can also behave differently depending on the magnetic properties of the material.
Generally, 300-grade stainless steel series is annealed for recrystallizing and here’s what you need to know about it:
Types of Materials That Can Be Annealed
To carry out this process, you can use only those materials that can be altered by heat treatments. Examples of these materials include steel and iron. Other types like copper, brass, and aluminum can also undergo this process.
The Process of Annealing
The annealing process falls into three stages. First, there is the recovery stage, then there is the recrystallization stage, and lastly, there is the grain growth stage. All three steps are discussed below.
The Recovery Stage
During this process, a furnace or any other device that can be used in the heating process is used to heat the metal and raise the temperatures of the metal to a point where internal structure and other stresses can be relieved.
After the temperatures have been increased in the recovery stage, it is further increased in the recrystallization stage. The temperature does not go beyond the melting point. This process results in the formation of new grains.
The Grain Growth Stage
During this process, new grains fully develop, this is enabled by letting the metal to cool at an identified rate.
After all the three stages are complete, the resulting material is more ductile and less hard. Other operations that can help substantiate this process are carried out after this process.
When to Use Annealed Materials
There are several applications of annealed materials. They can be used in machine processes that generate high volumes of heat or metal displacements that may need an annealing procedure later. The process can also be used in creating materials with unified physical properties.