Understanding Decarburization in Steel Materials and its Implications

Decarburization is a phenomenon that occurs when the carbon content on the surface of steel materials is significantly reduced due to oxidation at high temperatures. This oxidation process leads to the formation of a decarburized layer on the surface, which can have severe implications on the properties of steel materials.

Hazards of Decarburization

• Reduction in hardness and strength of cutting tools.
• Impaired wear resistance, cutting ability, and fatigue resistance of cutting tools.
• Decreased plasticity, resulting in cracking during forging or heat treatment of workpieces (cutting tools).
• Different internal and surface structures leading to internal stress and potential crack formation in workpieces (cutting tools).
• Reduced impact toughness, making cutting tools prone to brittleness and reducing their lifespan.
• Inaccurate hardness measurements due to the presence of the decarburized layer, impacting subsequent process planning and product quality assessment.
• Excessive depth of decarburization affecting the performance of workpieces beyond machining allowances.

Factors Influencing Decarburization:

• Furnace atmosphere: The oxidative of the atmosphere within the furnace can promote oxidation and decarburization of steel. Strongly oxidative atmospheres facilitate decarburization.
• Heating temperature: Higher heating temperatures accelerate oxidation and increase the depth of decarburization.
• Soaking time: Prolonged soaking or heating time results in deeper decarburization , but lower temperatures might have minimal impacts.
• Chemical composition of the steel: Higher carbon content in steel increases the susceptibility to decarburization. Trace elements such as Al, Si, Cb, and W promote decarburization, while Mn, Cr, Ni, Ti, and P hinder it. Steel types prone to decarburization include carbon tool steel, mold steel, high-silicon spring steel, bearing steel, and high-speed steel.

Prevent and Reduce Decarburization

Understanding the concept of decarburization in steel materials and its detrimental effects is crucial in ensuring quality and performance in various applications. By considering factors such as furnace atmosphere, heating temperature, soaking time, steel composition, and employing appropriate preventive measures, decarburization can be minimized or prevented, leading to improved product quality and longevity.

LUK Knives Blades continues to explore and improve the heat treatment process in order to create high-quality, wear-resistant blades. If you wish to upgrade your cutting machinery or have any questions about mechanical blades, please do not hesitate to contact us.