The blank from which the alloy screw is made should be forged and then annealed to eliminate the internal stress generated during forging of the steel.
①The blank from which the alloy screw is made should be forged and then annealed to eliminate the internal stress generated during forging of the steel.
②Alloying rods should be made of alloy steel or high-quality carbon structural steel with good performance and low deformation in high temperature environment, such as 38CrMoAIA, 40Cr or 45 steel.
③Roughness of alloy screw thread working surface roughness: the two sides of the thread are not more than 1.6μm, and the bottom and outer circle of the thread groove are not more than 0.8μm.
④The working surface of the threaded screw of the alloy screw is to be nitrided, the depth of the nitride layer is 0.3-0.6mm, and the hardness is HV700-840.
⑤After the alloy screw is finished, the accuracy of the outer circle should meet the accuracy requirement of 8 in GB180-79.
⑥After rough machining (turning), the alloy screw blank should be quenched and tempered, and the hardness is HB260-290.
⑦The alloy screw brittleness is not more than 2 grades.