Several maintenance methods for non-standard flange
1. Preheating:
1. For workpieces with complex shapes or sharp changes in cross-section and large effective thickness, preheating should be carried out
2. The methods of preheating are as follows: the first preheating is 800°C, the second preheating is 500~550°C and 850°C, and the temperature rising speed of the first preheating should be limited
2. Heating:
1. Workpieces with grooves and no holes, castings and weldments, and processed stainless steel workpieces are generally not suitable for heating in a salt bath furnace
2. There should be enough heat preservation time for workpiece heating, which can be calculated according to the effective thickness and conditional thickness of the workpiece (the actual thickness multiplied by the shape factor of the workpiece) referring to Table 5-16 and Table 5-17
3. Cleaning:
1. Workpieces and fixtures should be cleaned of oil, residual salt, paint and other foreign matter before heat treatment…