Heat treatment high strength fasteners should be quenched and tempered according to the technical requirements. The purpose of heat treatment quenching and tempering is to improve the comprehensive mechanical properties of fasteners, so as to meet the tensile strength value and yield ratio specified by the product. Heat treatment process has a crucial impact on the internal quality of high-strength fasteners. Therefore, in order to produce high-quality high-strength fasteners, we must have advanced heat treatment technology and equipment. Due to the large production capacity and low price of high strength bolts, and the thread part is relatively fine and relatively precise structure, therefore, the heat treatment equipment must have the ability of large production capacity, high degree of automation and good heat treatment quality. The reaction produces some oxidizing gases. For example, the surface rust of steel wire is composed of iron carbonate and hydroxide, which will decompose into CO2 and H2O after heating, thus aggravating decarburization.
The results show that the decarburization degree of medium carbon alloy steel is more serious than that of carbon steel, and the fastest decarburization temperature is between 700-800 ℃. Due to the fact that the attachment on the surface of steel wire decomposes into CO2 and H2O quickly under certain conditions,. Therefore, it is necessary to protect the top of the thread from decarburization during quenching and heating, and appropriately cover the decarburized fasteners with raw materials. The advantage of protective atmosphere in the mesh belt furnace should be adjusted to be basically equal to the original carbon content of the carbon coated parts, so that the decarburized fasteners can slowly recover to the original carbon content. The carbon potential should be set at 0.42% – 0.48%, and the carbon coating temperature is the same as that of quenching heating It can not be carried out at high temperature, so as to avoid coarse grains and affect mechanical properties.
High Stretch Structure Bolt,Heat treated high strength fasteners Material: Steel, Carbom steel 1045 Grade: 10.9,SAE GRADE 8 Surface: Black Diameter: M5-M36 Length: 6mm-500mm Tensile Strength: 1000Mpa Thread: UNC, UNF Finish: Plain, Zinc Plated(Clear/Blue/Yellow/Black), Black oxide, Nickel, Chrome, H.D.G. Our products quality control in strict accordance with the ISO9001 Quality […]
ASTM A193 Stainless Steel Metric Heavy Hex Bolt Stainless steel: SS210, SS304, SS316, SS316L, SS410 Certificate: ISO9001:2008, SGS, RoHS Grade: A2-70, A2-80, A4-70, A4-80 Finish: Polish, Passication Thread: Coarse,Fine Used: Building Industry Machinery Certification: ISO, ROHS, SGS Available Standard: DIN, ANSI, ASTM, JIS, BSW Strength: Grade 4.8,Grade 8.8, Grade10.9, Grade12.9 A2-70, A4-70, A4-80 Finishing: Yellow, blue, white zinc plated, Galvanized, HDG, Chromate, […]