Forging defects generated upon heating

Web Design And Seo For www.china-webdesign.com

thrust bearing - China Manufacturer

Thank you for inquiry my thrust bearing, Tel : 0086-0379-64390888, E-mail: liuping@lyzyc.cc

http://www.lyzycbearing.com/key-thrust-ball-bearings-41/

A beryllium oxide: beryllium oxide is not only the loss of a large number of steel, but also reduces the surface quality and the life of the forging die of the forging press-fitted inside the metal, will cause the forging scrapped. Not clear beryllium oxide will affect vehicle processing.
Decarburization: decarburization refers to the phenomenon of the whole or parts of the steel surface of the carbon is burned. Decarburization soft spots, so that the workpiece surface to reduce the surface hardness, wear resistance and fatigue strength.ball bearing suppliers

Overheating and overfiring: overheating refers to exceed the allowable temperature of the steel in the heating, so that the coarsening of the grain growth. Overheating is not conducive to heat treatment, the steel brittle and reduce the mechanical properties, but can be normalized or annealed after forging to eliminate. Overburnt refers to the heating time is too long, the temperature is too high, so that the metal oxide or a phenomenon of local melting. Overfiring can not be remedied.

Stress: metal, external heat, a n expansion is uneven, resulting in stress, said thermal stress. Heating caused by the changes in microstructure has also caused stress, said tissue stress. This will cause the workpiece in the cracks in the heating, caused the workpiece cracks vehicle processing and end-of-life.

5 - sectional fracture occurs: such defects destroy the steel chemical composition and uniformity, so that the quenching hardness is reduced, deterioration of the mechanical properties. Annealing temperature caused by graphite cross section, would not be easy machinability make harden overheating and deformation. But failed to finish due to heat or low temperature annealing, the pearlite globalization, is not conducive to cutting and subsequent heat treatment.ceramic ball bearing

6. Hard and brittle carbide network: it weakens the binding force between the crystal material, the mechanical properties signific antly deteriorate, in particular, so that the impact toughness is reduced, but can be improved by normalizing or eliminate. If there banded carbide, causes the hardness after quenching and tempering and tissue uneven and easily deformable, which is the pearlite and the ferrite along the machining deformation directions banded a defect appears. At the same time, it also reduces the ductility and toughness of the steel to make the car unstable machining dimensions, tool wear quickly.thrust bearings