Impact of work piece after magnetization on work
When not demagnetizing, longitudinal magnetization has magnetic poles at both ends of the workpiece, so longitudinal magnetization is more harmful than residual magnetization generated by circumferential magnetization. In the case of circumferential magnetization (such as magnetizing a round steel bar), the magnetic circuit is completely enclosed in the workpiece, and no leakage magnetic field is generated, but the residual magnetization in the workpiece is greater in the circumferential magnetization than in the longitudinal magnetization. This can be confirmed by measuring the residual magnetism in a longitudinal deep groove from the circumferentially magnetized workpiece, but the residual magnetism measured on the surface of the workpiece by the residual magnetometer is very small. Remaining magnetism on the workpiece will have a great impact on the further processing and use of the workpiece.
E.g:
(1) The residual magnetism on the workpiece will affect the accuracy and normal use of the magnetic compass and instrument installed near the workpiece;
(2) The residual magnetism on the workpiece will attract iron filings and magnetic powder, which will affect the roughness of the workpiece surface and tool life when processing continues;
(3) The residual magnetism on the workpiece will cause difficulty in removing the magnetic powder;
(4) The residual magnetism on the workpiece will cause the arc to blow in the arc welding process and the welding position will deviate;
(5) The residual magnetism of the oil circuit system will attract iron filings and magnetic powder, affecting the smoothness of the oil supply system;
(6) The residual magnetism on the ball bearing will attract iron filings and magnetic powder, causing the ball bearing to wear;
(7) The residual magnetism on the electroplated steel parts will cause the electroplating current to deviate from the expected circulation area and affect the electroplating quality;
(8) When the workpiece needs to be magnetized multiple times, if it is determined that the previous magnetization will have an adverse effect on the next magnetization.
Due to the above effects, the workpiece should be demagnetized. Demagnetization is the process of reducing the residual magnetism in the workpiece so as not to affect the degree of use. However, although there are residual magnetism on some workpieces, it does not affect the further processing and use, you can not demagnetize,
E.g:
(1) If the next process is heat treatment after the magnetic particle inspection of the workpiece, the workpiece must be heated to a temperature above 700 ° C (that is, it will be heated above the Curie temperature)
(2) The workpiece is a material with low remanence and high permeability, such as the workpiece of pressure equipment welded with low-carbon steel and the cylinder block of the locomotive;
(3) The residual magnetism of the workpiece does not affect the use;
(4) The workpiece will be in the vicinity of a strong magnetic field;
(5) The workpiece will be clamped by the electromagnet;
(6) Between two magnetization processes of alternating current;
(7) The magnetization of direct current is twice, and the magnetization of the rear track uses a greater magnetic field strength.
20" Magnesium Aluminum Luggage
Chongqing Sungrace International Trading Co.,Ltd , https://www.sungracetrading.com