离心铸造高锰钢偏心套热裂纹的成因与措施

Centrifugal Casting Process for Eliminating Hot Crack in High Manganese Steel Eccentric Sleeves

针对高锰钢偏心套在离心铸造过程出现的热裂缺陷,采用调温铸型,获得了无裂纹的高锰钢偏心套。结果表明,离心铸造金属型可加快偏心套外层的凝固速度,促使偏心套从外层向内层逐层凝固,降低了层间因凝固顺序不同导致的径向拉应力。同时,调温铸型通过对偏心套薄壁部分的保温以及厚壁部分的散热,平衡了不同壁厚区域的凝固速度差异,降低了厚壁热节对薄壁区域引起的切向拉应力,有效抑制了偏心套的开裂。

In order to eliminate hot cracks in the high manganese steel eccentric sleeves during centrifugal casting,a temperature-adjustment mould was used to prepare eccentric sleeves with absence of cracks.The results reveal that the radial tensile stress in inter-layer resulted from different solidification sequence in the middle of eccentric sleeves can be decreased through increasing solidification speed of outerlayer and promoting the sequential solidification from outer to inner layer.And the temperature-adjustment mould can reduce the tangential tensile stress by thermal insulation for thin wall and cooling for thick wall to decrease the solidification speed difference of different wall-thick zone.Both of the two ways can decrease the tendency of the hot crack for eccentric sleeves.