Common defects and remedial measures in the quenching process of stainless steel pipe fittings

　　In the heat treatment process of stainless steel pipe fittings, accidentally stainless steel pipe fittings will often appear some defects, thus affecting the quality of the heat treatment of the product, and even scrap, so it is necessary to take effective measures to prevent, and the defects that have appeared, to set up to save, the following focuses on the analysis of stainless steel pipe fittings quenching process common defects, And made the corresponding preventive and remedial measures.

　　Defects: overheating and overburning

　　Cause: Heating temperature is too high or heating time is too long

　　Preventive and remedial measures:

　　1. Correctly select the quenching heating temperature and heating time

　　2. The temperature of the opposite thermometer is calibrated regularly to prevent the occurrence of instrument failure and overtemperature

　　3. Reasonable furnace loading to prevent the workpiece from being too close to the heating body

　　Defect: hardening deformation

　　Cause:

　　1. The shape of the stainless steel casting workpiece is asymmetrical or the thickness is different

　　2. Large machining stress, not eliminated before quenching

　　3. Uneven heating and cooling

　　4. Improper heating clamping and cooling of the workpiece

　　5. The transformation of quenching tissue

　　Preventive and remedial measures:

　　1. Improve the structure of the workpiece, reasonable selection of materials, adjust the processing allowance, etc

　　2. Increase preheating or stress relief annealing process to carry out reasonable preliminary heat treatment

　　3. Adopt multiple preheating, pre-cooling quenching, double liquid quenching, fractional quenching and isothermal quenching and other operation methods

　　4. Correct operation, reasonable support bundling quenching heating workpiece, disperse cooling

　　5. The deformed workpiece is calibrated.