5results about How to "Avoid oxidation burn" patented technology

The present application relates to the field of energy-saving and environment-friendly production technology, in particular to a calcination method and system for flow-suspension roasting of petroleum coke. The method comprises: feeding petroleum coke raw materials into a multi-stage preheating system for countercurrent preheating; after preheating, the materials enter a flow-suspension roasting furnace to form a suspension state in a high-temperature airflow for rapid roasting; after roasting, the materials are separated from the flue gas, the separated flue gas containing volatile components is combusted in a combustion furnace and then subjected to purification treatment, and the heat is partially recycled; the separated high-temperature calcined coke is cooled through an air cooling and water cooling system and the heat is recovered, and the hot air generated by air cooling is recycled to the roasting furnace. The present application uses fluidization technology to shorten the roasting time to seconds, significantly improving the production efficiency; through multi-stage countercurrent heat exchange, flue gas combustion and heat recycling, the present application realizes heat cascade utilization and precise atmosphere control, greatly reduces energy consumption and oxidation loss, and stably controls the volatile component of the product below 1%, with high yield and uniform quality.

The application provides a rare earth-titanium-boron composite vacuum seal welding high-density cored wire and a preparation method thereof, and belongs to the technical field of metallurgical auxiliary materials. The preparation method comprises the following steps: weighing lanthanum-cerium rare earth alloy powder, titanium powder and boron powder for batching, and then uniformly mixing under a protective atmosphere to obtain mixed powder; filling the mixed powder into a low-carbon steel cylinder after pretreatment under a protective atmosphere, and then preliminarily sealing to obtain a composite blank; performing a reduction reaction on the composite blank in hydrogen, and then performing seal welding under a vacuum condition to obtain a composite blank after vacuum seal welding; heating the composite blank after vacuum seal welding, and then performing hot drawing to obtain the cored wire. The cored wire provided by the application realizes stable composite addition of rare earth, titanium and boron with high recovery rate, and significantly improves the structure and performance of 20Mn2 steel and the like, and solves the problems of cold heading cracking, insufficient toughness and aging embrittlement.

The application relates to the technical field of alloy materials, in particular to a 4341E high-speed steel and a preparation method thereof. The high-speed steel is characterized in that Ti, B and N elements are introduced for ternary micro-alloying and synergistic modification on the basis of a W-Mo-V-Co component system, nanoscale particles generated in-situ by Ti-N are used as heterogeneous cores to significantly refine grains, the grain boundary is strengthened by the grain boundary segregation effect of boron elements, and the reticular carbide is effectively broken. The obtained steel material realizes perfect matching of high hardness, excellent red hardness and excellent impact toughness, solves the problem that the strength and toughness of traditional high-speed steel are difficult to be compatible, and is particularly suitable for manufacturing high-performance cutting tools, cold and hot precision dies and high-temperature wear-resistant parts.

The application discloses a kind of plasma arc welding torch, to solve the technical problems of poor cooling effect of existing welding torch, nozzle disassembly and maintenance are complicated, tungsten needle is low, the service life of gun body is short.It includes gun body assembly and the gun head assembly detachably mounted on gun body assembly, tungsten needle, centering device, nozzle, tungsten needle limiting component and cooling waterway component are arranged in gun head assembly;Cooling waterway component constructs independent negative electrode, positive electrode double cooling waterway, adopts sectional type surrounding flow channel design;Nozzle is provided with annular positioning boss, and forms two-stage coaxial limiting system with centering device, gun body assembly integrates independent ion gas, double gas path structure of shielding gas, and the tail of gun adopts integrated linkage quick-release structure.The application greatly improves the cooling efficiency of welding torch and the centering accuracy of tungsten needle under the premise of ensuring compact structure, realizes quick disassembly and maintenance of wearing parts, effectively prolongs the service life of welding torch, and can be widely adapted to various high-load continuous welding industrial scenes.

This invention discloses an exothermic welding device for zinc-clad steel grounding electrodes of buried gas pipelines, belonging to the field of exothermic welding technology. Molten metal inside the reaction chamber flows into the welding cavity through a guide hole. A first interface channel for inserting the zinc-clad steel grounding electrode is machined on one side of the welding mold. A squeezing and vibration mechanism located on the outer circumference of the zinc-clad steel grounding electrode is installed inside the first interface channel. A second interface channel for inserting a connecting wire is machined on the other side of the welding mold. One end of the zinc-clad steel grounding electrode inside the welding cavity is connected to one end of the connecting wire to form the welding part. This invention, through inert gas pre-purging, can completely remove air from the welding cavity, avoiding oxidation and burn-off of the molten copper at temperatures above 2000℃ upon contact with air. This effectively reduces defects such as porosity and oxide inclusions inside the weld. The molten copper solidifies stably in an inert environment, forming a metallurgical-grade cast-welded connection, with stable and reliable conductivity and mechanical strength of the joint.