【摘要】 电磁离心铸造HK40钢管的凝固组织由外层的倾斜柱状晶和内部等轴晶组成,随着励磁电流的增大,柱状晶偏斜角增加,等轴晶晶粒变细,晶界共晶碳化物数量增加,时效析出二次碳化物减少。在3A的励磁电流搅拌作用下,共晶碳化物引起的晶界强度和二次碳化物引起的晶内强度获得最佳配合,使HK40离心铸管蠕变抗力最大,增加或减少励磁电流都会使蠕变抗力降低。更多还原

【Abstract】 The solidification structure of HK40 steel obtained by EMCC(electro-magnetic centrifugal casting) consists of equiaxed grains in the interior wall and incline columnar grains in the out wall of the tube. As the exciting current increases, the slanting angle of the columnar grains increases and the size of the equiaxed grains decreases. With the increase of the exciting current, volume fraction of eutectic carbides at grain boundaries increases and secondary carbides within grains after aging decrease. Maximum creep resistance of HK40 steel is obtained by EMCC under the middle exciting current of about 3A. This can be attributed to optimum coupling of grain boundary strengthening by eutectic carbides and precipitation strengthening by secondary carbide within grains.更多还原