Detailed introduction

01

2018

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08

What are the requirements for the manufacturing quality of the screw


 
  ScrewWhat are the manufacturing quality requirements?
① The screw of the extruder should be made of alloy steel with small thermal deformation, wear resistance and corrosion resistance. Commonly used materials are 38CrMoAlA alloy steel or 40Cr steel, repair parts can also be made of 45 steel.
② The material blank for screw shall be formed by forging method.
After the screw is machined, the excircle accuracy should reach the 8 level (GB 180-79) accuracy quality requirements.
④ The coaxiality error between the working shaft surface of the connecting part of the screw and the transmission shaft and the outer circle of the screw thread shall not be more than 0.01mm.
⑤ Roughness of working surface of screw thread part R. Value: both sides of the thread shall not be more than 1.69m, and the bottom and outer circle of the thread shall not be more than 0.8/1m.
If the use of low-carbon alloy steel material manufacturing screw, in order to improve the hardness of the thread working surface and corrosion resistance, wear resistance, the thread surface to be nitrided, nitride layer deep 0.3~0.6ram, surface hardness of 700 ~ 840HV. The brittleness is not more than Grade 2.
⑦ 0.3MPa hydraulic test shall be conducted at the connection of the screw inner hole, and no water leakage shall be allowed for 5min.