66results about How to "No softening" patented technology

A preparation method of a carbon-carbon composite material with high thermal conductivity comprises the following steps: parallelly arranging mesophase asphalt-based carbon fibers in a flat plate, uniformly spreading a layer of condensed polynuclear aromatic hydrocarbon resin powder on the mesophase asphalt-based carbon fibers, heating the resin powder for fully melting so as to coat a resin film layer on the fiber surface, naturally cooling to obtain a carbon fiber preform; or dissolving the condensed polynuclear aromatic hydrocarbon resin by an organic solvent to prepare a solution, soaking the mesophase asphalt-based carbon fibers in the solution, completely volatilizing the solvent to form a resin layer on the fiber surface so as to obtain the carbon fiber preform; cutting the carbon fiber preform into thin sheets according to a desired dimension, orderly stacking the sheet-like carbon fiber preform in a mold, performing pressurization to 20-70 MPa, heating to 110-145 DEG C, performing depressurization, maintaining for 0.5-2 hours, heating again to 200-300 DEG C, curing for 1-6 hours, after curing, naturally cooling to room temperature for demolding, performing carbonization at 900 DEG C of the obtained cured sample, soaking the sample with asphalt at a soaking temperature of 340-400 DEG C for soaking time of 1-8 hours, repeating the carbonization-soaking cyclic process to increase the sample density to 1.5-1.7 g / cm3, and performing graphitization to prepare the carbon-carbon composite material with high thermal conductivity. The invention has the advantages of low energy consumption and high thermal conductivity.

The invention relates to 390 MPa-grade polar hull structural steel with low-temperature toughness and a preparation method of the 390 MPa-grade polar hull structural steel, and belongs to the technical field of microalloyed steel. The steel and the method are used for solving the problems that an existing steel type cannot meet the polar environment temperature use condition and the production cost is high. The method comprises the following steps that 1, molten iron pretreatment is carried out; 2, high-quality scrap steel is added, a converter is adopted for smelting, Al is adopted in a steelladle for deep deoxidation, and ferrocolumbium is added after deoxidation; 3, alloying treatment is carried out; 4, whole-process protection pouring is adopted in the continuous casting process, thesuperheat degree of molten steel is guaranteed to range from 10 DEG C to 30 DEG C, the casting speed is controlled to range from 0.6 m / min to 1.5 m / min, and the strength of secondary cooling water isadjusted so that the temperature of the molten steel can range from 920 DEG C to 970 DEG C; and 5, controlled rolling and controlled cooling are carried out, and the polar hull structural steel is prepared. According to the hull structural steel prepared through the method, the yield strength is larger than or equal to 390 MPa, the impact energy at the quarter position of -100 DEG C is larger thanor equal to 200 J, the impact fracture fiber rate is larger than or equal to 80%, and the hull structural steel can be used for building ships serving in polar regions.