9 results about "Pearlite" patented technology

The invention discloses a manufacturing process of a high-carbon tool steel SK85 cold-rolled wide steel strip. The process is characterized in that steel is subjected to converter smelting, LF furnacerefining and slab continuous casting to obtain continuous casting slabs with the thickness ranging from 210 mm to 230 mm, the continuous casting slabs are heated and subjected to hot continuous rolling and laminar cooling to reach the coiling temperature, a hot-rolled wide steel strip with the thickness ranging from 2.5 mm to 6.0 mm is obtained, the coiled hot-rolled wide steel strip is put in storage and slowly cooled to the room temperature, and the obtained metallographic structure is thin-sheet-shaped pearlite; the total reduction of first cold rolling is controlled to be 20%-50% after acid pickling of the hot-rolled wide steel strip, then spheroidizing annealing is conducted, the Vickers hardness HV5 is 180 or below, and the spheroidizing rate is 92% or above; after the steel strip is subjected to primary spheroidizing annealing, secondary cold rolling is conducted, the total reduction of cold rolling is controlled to be 30%-85%, and a cold-rolled wide steel strip with the finished product specification being 0.70-3.00 mm thick is obtained; the steel strip subjected to secondary cold rolling is further spheroidized and annealed, the Vickers hardness HV5 is 175 or below, and the spheroidizing rate is 94% or above; and then third cold rolling is conducted, the total reduction of cold rolling is controlled to be 50%-85%, and the cold-rolled wide steel strip with the finishedproduct specification being 0.10-0.70 mm thick is obtained.

The invention discloses a production technology of a wire rod for solid surfacing welding wires. The wire rod comprises the components in percentage by weight as follows: 0.32-0.39% of C, 1.10-1.40% of Si, 0.80-1.10% of Mn, 1.10-1.40% of Cr, smaller than or equal to 0.025% of S, smaller than or equal to 0.025% of P, smaller than or equal to 0.30% of Ni, smaller than or equal to 0.25% of Cu, smaller than or equal to 0.10% of Mo and the balance of Fe and inevitable impurities. A process route comprises blowing by a converter, refining by an LF (ladle furnace), continuous casting and high-speed wire rolling. The solid surfacing welding wires produced through the technology have the advantages of low production cost, high deposition and welding efficiency, convenience in automatic operation and the like; according to the production technology of the wire rod for the solid surfacing welding wires, the component design of medium carbon and high silicon and chrome is adopted in chemical component, and the cost increase caused by addition of a large number of Ni, Mo, V, Ti alloys and the like in the past is avoided, so that the production technology has obvious economic benefits; the produced wire rod is stable in mechanical property, the tensile strength is 840-890 MPa, the elongation is 17%-20%, the area reduction is 60%-70%, the metallographic structure is F (ferrite) +P (pearlite), the grain size is grade 8.0-9.0, and the size deviation is + / -0.15 mm.

The present invention provides a high strength bolt that has excellent hydrogen embrittlement resistance. The high strength bolt having excellent hydrogen embrittlement resistance which bolt comprises 0.20 to 0.60% of C, 1.0 to 3.0% of Si, 1.0 to 3.5% of Mn, higher than 0% and not higher than 1.5% of Al, 0.15% or less P, 0.02% or less S, and balance of iron and inevitable impurities, and the structure includes: 1% or more residual austenite; 80% or more in total content of bainitic ferrite and martensite; and 10% or less (may be 0%) in total content of ferrite and pearlite in the proportion of area to the entire structure, and also the mean axis ratio (major axis / minor axis) of the residual austenite grains is 5 or higher and the bolt has tensile strength of 1180 MPa or higher.

The invention provides a novel microbial seedling medium and a preparation method and application thereof. The novel microbial seedling medium is prepared from the following raw materials of microbial probiotics (having the capability of inhibiting bacteria, producing IAA (Indoleacetic Acid) and dissolving inorganic phosphorus), peat, vermiculite, pearlite, mushroom residue, composted chicken manure and water. No any chemical pesticide or fertilizer are added in the novel microbial seedling medium, and the environment is not polluted. The novel microbial seedling medium disclosed by the invention has the advantages that soil can be improved, the fertilizer efficiency can be increased, the soil of the root of a plant is enabled to be fluffy and not to harden, water retention and fertilizer retention are realized, and healthy and strong growth of the root is promoted; the novel microbial seedling medium enables vegetables to be tidy and strong in seedlings, deep green in leaves, developed in root system, loosened in texture, good in air permeability, good in root development, comprehensive in nutrition, high in yield and light in pest and disease damage, and the novel microbial seedling medium is an ideal medium for producing green and organic vegetables.