Defects and remedial measures after heat treatment of stainless steel castings


Release time:

2024-04-18

From the box type, trolley type resistance furnace furnace plate, before use to a high temperature tempering, and try to control the temperature above 950 degrees, the purpose is to eliminate the internal stress in the casting process. Moreover, during the use of the furnace plate, it is necessary to ensure that the workpieces are placed evenly, and the workpieces cannot be stacked in a certain local position, otherwise it will cause the furnace plate to be uneven in the heat dissipation process during the heating process, which will easily cause the furnace plate to deform and crack. Reduce the service life of the furnace floor. Stainless steel casting manufacturing is smelting, casting, heat treatment to complete, casting steel should be this Ayong induction furnace, electric arc furnace, ladle refining furnace melting or its.

From the box type, trolley type resistance furnace furnace plate, before use to a high temperature tempering, and try to control the temperature above 950 degrees, the purpose is to eliminate the internal stress in the casting process. Moreover, during the use of the furnace plate, it is necessary to ensure that the workpieces are placed evenly, and the workpieces cannot be stacked in a certain local position, otherwise it will cause the furnace plate to be uneven in the heat dissipation process during the heating process, which will easily cause the furnace plate to deform and crack. Reduce the service life of the furnace floor.

 

Stainless steel castings are manufactured by smelting, casting and heat treatment. Steel for castings should be melted by Ayong induction furnace, electric arc furnace, ladle refining furnace or other smelting methods that meet the requirements. In the casting process in the demand side without special requirements, by the supplier to determine. The method of heat treatment is that the casting should be heat treated, usually, the heat treatment is carried out by the supplier. In case of defect removal and repair welding, we shall implement the following regulations:

 

1. The casting should be cooled to a certain temperature in the mold, and the martensitic steel should be removed from the surface after softening and annealing.

 

2. When removing defects, the minimum preheating temperature of castings shall be as specified in Table 2.

 

3. Casting defects are allowed to be repaired by repair welding. Before repair welding, all defects shall be removed to expose the dense metal surface.

 

4. Repair welding shall be carried out with the same or similar welding rod as the casting material.

 

5. When the same material martensitic welding rod is used for repair welding, defects and remedial measures after heat treatment of stainless steel castings are generally carried out after softening annealing and before final heat treatment. Unless otherwise specified, stress relief treatment after welding shall be carried out after welding with martensitic welding rod.

 

6. For chromium, manganese and nitrogen steel castings requiring intergranular corrosion tendency test or impact toughness test or both, solid solution treatment shall be carried out after repair welding.

 

The chemical composition of stainless steel castings shall comply with the national regulations. When the buyer needs to analyze the chemical composition of the finished product, the allowable deviation of the chemical composition shall comply with the provisions of Table 4. The mechanical properties of castings after heat treatment shall conform to the provisions of Table 5, and the surface hardness shall not be used as the basis for acceptance. The surface quality roughness of stainless steel castings shall comply with GB/T 6060.1. Casting defects such as cracks, cold insulation, pores and sticky sand are allowed on the surface cloth of castings. The dimensional tolerance of castings shall comply with the provisions of GB/T 6414.