The grades in this group are the only major alloy group containing between 11 percent and 17 percent chromium. These products show some similar aspects with ferritic groups. But the 0.10 - 0.65% carbon it contains is known for changing the reaction of the group most radically. Extremely high carbon can become harder with heat treatment.
Like many high carbon steels, 420 grade stainless can be further hardened by heat treatment. This stainless, which has a level of 50 Rockwell hardness with heat treatment, is soft enough to be called good when annealed. The best corrosion resistance is achieved by cleaning and hardening or polishing the surface. The welding capability of martensitic stainless steels, which are the most suitable group for high hardness, is also very poor and after welding, hardening with some annealing process is required. Martensitic Stainless Steels also have lower levels of corrosion resistance compared to the Austenic group.
In addition, Martensitic Stainless Steel material is also efficient and may lose some softness at temperatures below zero. In this case, its durability at high temperatures also decreases. In these cases, it is more appropriate not to use it.
The main norms are AISI 410 - 420.
Today, the use of steel continues to become more widespread day by day. While steel is divided into different classes, it can be preferred in this field depending on the sector of use. In some sectors, durability must be at the highest level, while in others, temperature resistance is required. On the other hand, many features such as a good level of stainless steel and a low level of fracture can be sought by the sectors.
Martensitic stainless, one of the steel types, is an alloy created for sectors where durability and longevity are required. In this way, the products created in this way switch between products that can be used over a long period of time. One of the most widely used types of steel is the type of steel known as martensitic. Just like other types of steel, it is seen as a product that stands out with its different properties and durability levels. If chromium and water are given to stainless steel over the highest temperatures, this will directly turn into a martensitic structure.
Martensitic structure is harder than others and has a very good structure in terms of durability. However, its fragility is also very high. It should be noted that the level of fragility is higher than others. Since excessive hardness will also cause brittleness, the hardness rate can be reduced slightly by annealing method during manufacturing. In this way, the strength of martensitic stainless steel can be adjusted at a desired level. Its corrosion resistance is at a medium level, but it has a formable structure compared to some steel types. Thanks to heat treatments, the desired results can be achieved by changing the mechanical and visual aspects. On the other hand, it also has a distinctive feature among other steel products. It has a structure that is a little more prone to rust than others. Especially in long-term use, these disadvantages can be very obvious.
Since this type of steel has a very good level of hardness, it is mostly used in sectors that require it. In the knife sector, this material is often used in surgical instruments that require durability. In this way, with the help of the alloy, a very good advantage can be obtained, especially in items where durability is most important.
