稀土钇对4.5％Si无取向硅钢成品板组织和磁性能的影响

采用4种不同稀土钇（Y）质量分数(0、0.006 %、0.012 %、0.016 %)的无取向4.5 %Si钢，探究了稀土Y对4.5 %Si钢成品板微观组织和磁性能的影响。研究表明，稀土Y可以将纳米级方形TiN、Al2O3夹杂物有效变质为球状TiO2、Al2O3、Y2O2S复合夹杂物，粗化夹杂物的尺寸，减少0~500 nm弥散细小的夹杂物的数量，因此添加适量Y可以使得4.5 %Si钢成品板晶粒长大速率加快，晶界迁移激活能减少，磁畴与晶界和夹杂物的相互作用的损耗减少，铁损降低。但过量Y会使细小夹杂物继续增多，晶界钉轧作用增强，成品板晶粒尺寸降低。在退火过程中，由于{111}取向晶粒易在微细夹杂物附近优先形核长大，稀土的添加降低了夹杂物密度，且稀土在晶界的富集减小了{111}晶粒在晶界的形核优势，因此稀土Y的添加削弱了γ织构的强度。结果表明，含0.012 %Y的试样的B50最高为1.655 T，在各频率下的铁损最低，分别为P1.0/50=1.41W/kg、P1.0/400=19.28 W/kg、P1.0/1000=77.69 W/kg。

Effect of rare earth Y on microstructure and magnetic properties of 4.5 % Si non-oriented silicon steel sheets#br#

Four kinds of non-oriented 4.5 % Si steels with different mass fraction of Y (0, 0.006 %, 0.012 %, 0.016 %) were analyzed for the effects of Y on microstructure and magnetic properties of annealed sheets. The results showed that Y effectively modified nano scale square TiN and Al2O3 inclusions into spherical TiO2, Al2O3 and Y2O2S composite inclusions, coarsened the size of inclusions and reduced the number of fine inclusions dispersed in 0-500 nm. Thus, adding appropriate amount of Y increased the grain growth rate and reduced the activation energy of grain boundary migration, and the interaction of magnetic domain with grain boundary and inclusions led to the decrease of loss and iron loss. However, excessive Y increased the fine inclusions, enhanced the effect of pinning grain boundary and reduced the grain size of the annealed sheets. The {111} oriented grains nucleated and grew preferentially around the fine inclusions during annealing, the addition of rare earth Y reduced the inclusion density, and the enrichment of rare earth Y at the grain boundary reduced the nucleation advantage of {111} grains at the grain boundary, so the addition of rare earth Y weakened the strength of γ texture. The results showed that the sample containing 0.012 % Y has the highest B50 (1.655 T) and the lowest iron loss at each frequency, P1.0/50=1.41 W/kg, P1.0/400=19.28 W/kg and P1.0/1000=77.69 W/kg respectively.