3results about How to "Prevent respawn" patented technology

The invention discloses a control method for a transverse corner crack of a niobium-containing steel casting blank, which comprises the following steps: controlling the argon blowing flow of a long nozzle to be 200-300 l / min, controlling the argon flow between tundish plates to be 20-40 l / min, and adding a covering agent after the molten steel of the tundish is discharged to 10 tons and submerges the lower opening of the long nozzle; starting up the furnaces to add 200-350 kg of the casting blank, 100-200 kg of a stopper rod area and 100-150 kg of an impact area, adding 100-150 kg of the impact area in the second furnace, 80-100 kg of the casting blank in the third furnace and 50-80 kg of the casting blank in the fourth furnace, reducing the secondary cooling water in the third furnace to 100-150 l / min, increasing the surface temperature of the casting blank to 1000 DEG C or above during bending, increasing the surface temperature of the casting blank to 50-80 l / min during straightening, and increasing the surface temperature of the casting blank to 950 DEG C or above during straightening; the degree of superheat of a starting or inserting head furnace is less than or equal to 40 DEG C;

This invention discloses a raw material pretreatment method for zone melting purification of high-purity aluminum, belonging to the field of non-ferrous metal refining technology. The pretreatment method includes alkaline washing, acid neutralization, cleaning and drying, and vacuum-protected loading steps. High-purity aluminum raw material is immersed in a 5-8% sodium hydroxide aqueous solution at room temperature for 5-30 seconds, and removed when bubbles begin to form on the substrate. The alkaline-washed aluminum material is then immersed in an 8-12% nitric acid or acetic acid aqueous solution for neutralization for 10-20 seconds. After acid neutralization, the aluminum material is cleaned and dried, then placed in a zone melting furnace. A vacuum is drawn, and inert protective gas is introduced to atmospheric pressure or a slightly positive pressure. This method thoroughly removes oxide scale from the surface and bonding surfaces of the aluminum material, effectively preventing secondary oxidation during post-treatment transfer and loading. It creates continuous and unobstructed molten pool propagation conditions for the zone melting process, ensuring the smooth progress of the purification process and the high quality of the final product. This method is particularly suitable for eliminating oxide scale on the bonding surfaces of segmented aluminum rods to ensure the smooth operation of the zone melting process.

The embodiment of the invention relates to the technical field of rubber flocculation, and discloses low-Mooney high-performance natural rubber and a preparation method thereof, and the preparation method adopts fresh latex, a clastic enzyme and a flocculant to prepare the natural rubber. The natural rubber with low Mooney viscosity and high performance is prepared through the matching of the decomposition enzyme and the flocculating agent. The raw materials adopted in the method are few in variety and easy to obtain, and the cost of the raw materials can be reduced. Meanwhile, the raw materials adopted by the preparation method are environment-friendly and are not easy to cause pollution.