1. Galvanized pipes and fixtures should remove foreign objects such as oil, residual salt, and paint before thermal treatment;
2. The fixture used in the vacuum furnace for the first time shall be carried out in advance at the vacuum of the vacuum required by the workpiece;
3. In the workpiece that is easy to deform during thermal treatment process, heating should be performed on a dedicated fixture. The preheating method is: 1 preheating at 800 ° C, and the secondary preheating at 500-550 ° C and 850 ° C. The temperature speed speed at a time should be limited;
4. For workpieces with a sharp change in the shape or cross -section, and the effective thickness workpiece, preheating should be performed;
5. Workers, castings and welded parts with no pores, and stainless steel workpieces that are processed and forming are generally not suitable for heating in a salt bath furnace;
6. According to the effective thickness and condition thickness of the workpiece (the actual thickness is multiplied by the shape coefficient of the workpiece), the heating of the galvanized pipe should have sufficient insulation time;
7. Martiner's stainless steel and heat -resistant steel galvanized pipe quenching it is cold until room temperature can be cleaned, deep -cold treatment or recovery. The time interval between welding and subsequent heat treatment shall not exceed 4 hours;
8. Clean alkaline washing, water -soluble cleaning agent, chlorine solvent, spray and other methods according to the requirements and surface conditions of galvanized pipes;
9. After correction, the dehuminar reduction should be performed below the original fire temperature. The shape is complicated or the size requires strict workpieces. After correction, use a fixed fixture to combine the fire to correct it;
10. When the performance of galvanized pipeline is unqualified, repeated thermal treatment can be performed, but the number of repeated quenching or solid solution is generally not more than twice. The replenishment of the galvanized pipe is not counted as repeated treatment. The quenching status or low -temperature recovery of mate -generated stainless steel and heat -resistant steel workpiece should be preheated before repeated quenching, annealing or high temperature recovery.
