Q420 steel is a high-carbon alloy made from low-carbon steel. It is widely used in automotive, construction and aviation industries for its good performance and long service life at high temperature and pressure. The alloy has a very high tensile strength and can be hardened with a laser heat treatment process.
Q420 steel is a ferritic stainless steel, meaning it has a high resistance to corrosion. It is often used in environments where there is a potential for corrosion due to high temperatures, extreme pressure, and exposure to certain chemicals. The alloy is also heat-treated at very high temperatures to achieve a greater resistance to corrosion, as well as improved wear resistance, making it a great choice for parts that need to stand up to heavy use.
Heat treatment is an important step in the alloy development process that allows the steel to be strengthened to its maximum potential. This is done by heating and cooling it at different temperatures to increase the crystalline structure and grain boundaries, making it more durable and stronger.
The alloy can then be given a laser heat-treatment process to increase its overall durability and strength. This process involves exposing the steel to a high-powered laser beam that is used to activate the material and create a hardening reaction. This hardening process allows the steel to become more resistant to damage and wear, making it an ideal choice for parts that need to withstand harsh conditions.
The alloy is also capable of undergoing a tempering process in order to increase its resistance to fatigue. This involves heating the steel at high temperatures and then allowing it to cool slowly while under pressure. This process increases the fatigue strength of the material and reduces its brittleness, making it better suited for applications that require it to be exposed to dynamic stress.
The microstructure of Q420 steel is ferritic, meaning that its grain structure is composed of fine ferrite particles with a high percentage of chromium and nickel added to it. The ferritic microstructure allows for a greater grain contact between the alloy particles, which increases the strength of the material.
The laser heat treatment process also produces an even grain boundary contact as well as a better grain boundary alignment, leading to a stronger and more durable alloy. The benefits of the laser treatment process are that it makes the alloy stronger and more resistant to wear, as well as improving its fatigue strength and making it better able to withstand dynamic stress.
The microstructure of Q420 steel is comparable to those of other similarly-treated steels, such as AISI 1040, AISI 1045, and AISI 1060. The grain structure of the alloy exhibits a higher amount of chromium and nickel as compared to other similarly-treated steels. A comparison of the microstructure of the alloy with that of similarly heat-treated steels can be found in the accompanying gold micrograph.
The gold micrograph highlights the ferrite particles and indicates the texture of the material. The grain boundaries are clearly visible and the overall grain contact between the alloy particles is well-developed, with the grain boundaries being offset and in contact with each other.
The laser heat treatment process has been beneficial for the production of Q420 steel, which is now a suitable choice for many applications. Thanks to its high tensile strength, improved mechanical properties and good resistance to corrosion and fatigue, it is a desirable option for many industries where it can help to prolong the service life of parts.
