For the detection of some special purpose steel metal products, we need to consider the detection of its magnetic properties first. For example, various silicon steel sheets (soft magnetic materials), permanent magnets (hard magnetic materials) for various electrical instruments, and various machine parts (weak magnetic or non-magnetic materials) that are required not to be affected by the magnetic force, etc. when testing these metal products, it is necessary to determine their magnetic properties according to their use to know whether they meet our performance requirements, or to avoid some mechanical properties or Mechanical defects.
1、 Magnetic property test standard
At present, the national and ministerial standards for magnetic property measurement include GB / T 24270-2009 temperature coefficient measurement method of permanent magnetic material magnetic property, GB / T 10129-2019 medium frequency magnetic property measurement method of electrical steel strip (sheet), GB / T 3655-2008 Epstein square circle measurement method of electrical steel strip (sheet), GB / T 3658-2008 circular test method of AC magnetic property of soft magnetic material, GB / T 13012-2008 method for measuring the DC magnetic properties of soft magnetic materials, GB / T 13789-2008 method for measuring the magnetic properties of electrical steel sheet (strip) with a single-chip tester, GB / T 19346-2003 method for measuring the AC magnetic properties of amorphous nanocrystalline soft magnetic alloys, etc.
2、 Key test items of magnetic properties
Among all kinds of magnetic materials, the emphases of different materials are different. Next, we will introduce the key test items of soft magnetic materials, hard magnetic or permanent magnetic materials, weak magnetic or non-magnetic materials.
1. Soft magnetic materials (electrical silicon steel sheet, electrical pure iron, etc.) are important magnetic properties testing items, mainly including magnetization curve, hysteresis loop, permeability, residual magnetic induction intensity, as well as magnetic induction intensity under certain magnetic field intensity and core loss under certain conditions (hysteresis loss, eddy current loss and residual loss, etc.);
2. The main performance test items of hard magnetic or permanent magnetic materials include residual magnetic induction strength, coercive force and maximum magnetic energy product after magnetization under certain magnetic field strength;
3. The main performance test items of weak magnetic or non-magnetic materials (including antimagnetic materials and paramagnetic materials) are permeability or susceptibility index.