Analysis of the main reasons for tempering deformation of annealing furnace

Analysis of the main reasons for tempering deformation of annealing furnace

When the quenched steel material is tempered, the cracks caused by the rapid cooling, rapid heating or structural changes are called tempering cracks. Common high-speed steel, SKD11 die steel and other tempered hardened steels will also produce rapid cooling after high-temperature tempering. This kind of steel produces matian bulk deformation during quenching, and during tempering, the second matian bulk deformation (remaining austrian bulk deforms into matian bulk) due to quenching, resulting in cracks. Therefore, it is necessary to prevent tempering cracks, cool slowly from the tempering temperature, and at the same time, avoid putting forward the heat treatment method of tempering and then quenching in advance in the operation of quenching and tempering.

Pay attention to the leading enterprises of construction machinery. In terms of investment strategy, we recommend the three leading companies of Sany Heavy Industry, Zoomlion, and Xugong Technology. Leading's product line is more complete and is less affected by the sales of a single product. More importantly, the leading enterprises have complete products and strong comprehensive strength. In the case of the decline in sales of original products, they can also achieve growth in sales revenue by adjusting product structure, adding new products, and extending the industrial chain.

The main reason for the tempering deformation is the residual hard force or the change of the structure in the annealing furnace during tempering, that is, the shrinkage due to the elimination of tensile stress and the expansion of compressive stress due to the tempering, including the precipitation in the initial stage of tempering. There will be some shrinkage of carbides, a large amount of shrinkage will occur during the condensation process of Xueming carbon iron, residual austenitic iron will transform into matian scattered iron and will expand, and residual austenitic iron will transform into toughened iron and will expand, etc., which will cause the workpiece to be damaged after tempering. Deformed. Prevention methods include: (1) implement pressure tempering treatment; (2) use hot bath or air quenching to reduce residual stress; (3) use mechanical processing methods to correct and (4) reserve deformation.