| 摘要 |
<p>1482546 Treating silicon steel KAWASAKI STEEL CORP 1 Oct 1974 [17 Nov 1973] 42645/74 Heading C7U An aqueous dispersion for coating a Si steel sheet comprises 7-24 wt per cent colloidal SiO 2 and 5-30 wt per cent Mg monophosphate. It may have added to it 0À01-5% of CrO 3 , a chromate or a dichromate. The composition is applied to the sheet and the resulting coating is baked at 350‹- 900‹C; this may be in two stages, e.g. first at 350‹- 600‹C and then at 800‹C to 900‹C, in a neutral or weakly oxidizing atmosphere, e.g. air. The surface of the steel is left in tension when the coating cools, thereby improving magnetostriction properties of the steel when under compression , e.g. in transformer cores.</p> |
