Flat square tube

Flat square tube products of the brazing tail heat treatment process:

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

Brazing tail tempering process: 320 ~ 340 ℃ ± 10 °. Tempered hardness HRC52-54. the chemical composition of the furnace batch of high carbon content (from the quality assurance can be found) is appropriate to use the high limit of temperature; low carbon content is appropriate to choose the low limit of temperature. Or after tempering check the braze tail hardness if higher than HRC54. to raise the temperature to re-tempering. If the hardness after tempering is lower than HRC48. the braze tail should be normalized and then re-quenched, the tempering temperature should be adjusted lower than the original. Braze tail tempering, special low-temperature salt furnace is recommended, local tempering, immersed in the salt bath length should not exceed the cone brazing shoulder, than the quenching length of 10 mm deep is appropriate.