Common sense problem of stainless steel pipe fitting

The best way to improve the quality of stainless steel pipe fittings is to change the casting process from ingot to billet. Due to the improvement of quality control means of continuous casting process, this method has become a necessary means to improve product quality.

Stain-less steel continuous casting billet quality advantages embodied in the surface outside in addition to the first paragraph billet grinding rate has reached more than 70%, the overall appearance grinding yield reached 99.15% in order to achieve this goal must to refining of molten steel, low oxygen and sulfur content, do well the bag and tundish metallurgy, accurately control the temperature of molten steel, casting without oxidation, further reduce the inclusion content.

The concrete steps of continuous casting slab technology for stainless steel pipe fittings are as follows:

1. According to different types of steel, the vibration process of the crystallizer should be matched with the protection slag, so as to improve the yield of molten steel by 10%, save energy and shorten the production cycle.

2. Continuous casting should be adopted for stainless steel pipe fittings, so as to improve the comprehensive rate of finished materials, and cooperate with the refining outside the furnace, significantly improve the production efficiency, but also omit the blanking process, saving a lot of energy consumption.

3. The continuous casting of stainless steel pipe fittings is generally matched with the refining furnace, which has strict requirements on the chemical composition and temperature of molten steel; In order to prevent secondary oxidation of molten steel, non-oxidation protection casting is required in continuous casting process. Refractory materials such as ladle, tundish, sliding nozzle and submerged nozzle are strictly required.

4. To ensure the appearance quality of continuous casting billet, select appropriate maintenance slag; In the process of continuous casting, the vibration marks formed on the surface of continuous casting slab due to mould vibration should be controlled. Electromagnetic stirring must be used in continuous casting of ferritic stainless steel pipe fittings.

5. After fine-tuning the temperature of molten steel at argon blowing station, it is hoisted to the rotary table of large ladle to wait for continuous casting.

6. After the molten steel casting, the stainless steel pipe fittings are generally used with the same vertical, vertical bending or arc continuous casting machine as carbon steel. After refining, the molten steel is poured into the tundish. The ladle to be poured is transferred to the top of the tundish injection port through the rotary table, and then the molten steel is injected into the tundish through the long nozzle. The molten steel in the tundish passes through the submerged nozzle into the crystallizer for forming, condensation and continuous downward movement.

After the solidified surface slab continues to be rapidly cooled in the secondary cooling section and the core of the slab is solid, fixed-gauge flame cutting is carried out to complete the continuous casting process of the stainless steel pipe fittings.