On 2018-08-08 14:48:54
The quenching deformation and cracking can be reduced by graded quenching
Graded quenching, also known as hot bath quenching, can ensure the parts to obtain high hardness, and can make the parts to avoid cracking, do not occur or rarely produce deformation.
High flow (1OOL/m I n) oil pump gear, material is 40Cr steel, hardness is required to be 48~52HRC, inner hole deformation is required to be ≤ 0.05mm. The raw material is first normalised to prepare the tissue for quenching to reduce deformation.
Processing forming processing, as a result of quenching oil as a result of the change of tooth profile and inner diameter after processing difficulties, oil pump noise increased, later adopted in 820 ~ 7 m I n C heat insulation, quenching into 260 ℃ isothermal cooling in nitrate and remove after 2 0 m I n in air cooling, hardness can be up to 50-52 HR C, conform to the requirements, inner hole deformation can be controlled in the range of 0.03 ~ 0.05 mm.