Quenching is a way that steel with a certain carbon content changes its properties after it is heat treated:
The carbon content determines the hardness of the material after quenching. The higher the carbon, the higher the hardness after quenching. Commonly known as: hardenability.
It can also be understood that only steel with a certain carbon content can be quenched, and the carbon content is generally required to be greater than 0.1%. For example, 300 series, 0CR13 430 in the 400 series have low carbon content, so this type of steel cannot be quenched. Only carbon steel, steel above 1cr13 can be quenched. This type of steel changes the mechanical properties of the material through the quenching process to meet the needs of customers. Require.
The quenching process changes the material structure. The material before quenching is ferrite and has a body-centered cubic structure. For example, 2cr13, 3cr13, etc., these materials are heated. During the heating process, along with the decomposition of carbides, carbon atoms slowly merge into the ferrite matrix to form a supersaturated structure, which is a face-centered cubic structure. During the rapid cooling process , the supersaturated carbon has no time to precipitate, forming a face-centered cubic structure and transforming into a martensite structure.
Performance after quenching
Hardness The hardness of the material increases after quenching: 20cr13 HV : around 480 30cr13 HV : around 520 40cr13 HV : around 560 Note: The specific hardness needs to be determined by the customer's processing technology and requirements. |
Tensile strength Tensile strength is the main performance of the material after quenching. Generally, the tensile strength of 3cr13 after quenching can reach more than 1400, and the unquenched material is about 900. |
Anti-rust performance The anti-rust performance of martensitic steel after quenching is better than that of unquenched materials, mainly because after the carbon chromium decomposes, the carbon dissolves in the matrix, and the chromium element strengthens the anti-rust properties. Chromium is an element that plays a decisive role in rust prevention in 400 series stainless steel. Due to the presence of carbon chromium compounds before quenching, the actual chromium element that is responsible for rust prevention is about 2% lower than the actual content. After quenching, the chromium element content can increase by 1%. above. |
Wear resistance The high strength and density of the quenched material hardness matrix gives the material high wear resistance. From the perspective of cutting tools, cutting tools and other industries, most materials that require quenching have high wear resistance after quenching. |
