Introduction
410 stainless steel, with a grade of 3Cr13, is a martensitic stainless steel which is one of the most widely used in industry due to its good corrosion resistance, high strength and affordability. It is heat treatable and has a hardness of Rc28-35. Hardened 410 stainless steel has a tensile strength of 650-1350N/mm2 and it is usually used for components requiring high strength and wear resistance, such as knife blades, screws, valves and shafts.
Heat treatment of 410 stainless steel
410 stainless steel can be heat treated to increase its hardness and strength. The best results are achieved when it is quenched in oil at 1000°C and then tempered at 280°C. The quenching in oil increases the hardness and wear resistance, while the tempering increases the ductility and toughness of the steel. This combination of properties gives the steel its desired characteristics.
The microstructure of 410 stainless steel
At the microstructure level, the hardened 410 stainless steel is composed of martensite and secondary carbides. Martensite is the hardest and most wear-resistant phase of stainless steel and it is composed of highly strained ferrite. The secondary carbides are formed during the heat treatment and are composed of several metallic elements such as chromium and carbon. The secondary carbides improve the wear resistance of the stainless steel and stabilize the microstructure.
Metallographic analysis
A metallographic analysis can be performed to study the microstructure of the heat treated 410 stainless steel. This analysis involves the use of microscopic examination of a section of the steel which is corroded and then polished to a mirror finish. By observing the microstructure under a microscope, it is possible to identify the different phases of the steel, such as the martensite and the secondary carbides, and their size and distribution. This information can then be used to assess the quality of the heat treatment and make adjustments as necessary.
Conclusion
In conclusion, 410 stainless steel is a versatile and popular grade of stainless steel due to its relatively good corrosion resistance, strength and affordability. It can be heat treated to increase its hardness and strength by quenching in oil at 1000°C and then tempering at 280°C. The metallographic analysis of the heat treated material allows us to observe the microstructure of the steel, such as the martensite and secondary carbides, and assess the quality of the treatment.
