Heat treatment process of brazing tail of flat square controlled products

Heat treatment process of brazing tail of flat square controlled products：

The heat treatment of the drill tail is mainly to ensure that the drill tail does not pile up or explode under the high-frequency impact of the piston.For 55SiMnMo steel, when the hardness of the drill tail is in the range of HRC50-54, it will be able to meet the above requirements.The heat treatment process of the brazing tail of 55SiMnMo steel is: 870℃±20°.For oil quenching, the intermediate frequency induction coil can be used for quenching and heating, the heating length is 70~80 mm, and the hardness after quenching is HRC56-58.

Brazing tail tempering process: 320~340℃±10°.Hardness HRC52-54 after tempering.The chemical composition of the furnace batch has a high carbon content (as can be found from the quality assurance certificate) and a high temperature limit should be used; a low temperature limit should be selected for low carbon content.Or after tempering, check that the hardness of the drill tail is higher than HRC54, and adjust the temperature to re-temper.If the hardness is lower than HRC48 after tempering, the drill tail should be normalized and then quenched again, and the tempering temperature should be lowered than the original.For tempering the drill tail, it is recommended to use a special low-temperature salt furnace for local tempering. The length of the immersion salt tank should not exceed the cone drill shoulder, and it is appropriate to be 10 mm deeper than the quenching length.