一、绪言钢中 MnS 夹杂从其形态和分布一般可分成三类:球状的Ⅰ型往往与氧化物复合存在于含氧较高的钢中,由于固溶了氧而塑性较差,对钢板的厚向韧性等机械性能影响较小;Ⅱ型存在于氧浓度低的钢中,多数以共晶形态分布在树枝晶间。经受大的变形时形成所谓群集状的特殊分布,危害钢材的机械性能;角状的Ⅲ型与Ⅱ型一样存在于低氧浓度的钢中。虽然延性 I. INTRODUCTION MnS inclusions in steel can be generally divided into three categories from their morphology and distribution: the spherical type I is often complexed with oxides present in higher oxygen steel due to the poor plasticity due to solid solution of oxygen, Thickness to toughness and other mechanical properties less affected; Type Ⅱ exists in the low oxygen steel, most of the distribution in the form of eutectic dendrite. When subjected to large deformation, the formation of the so-called cluster-like special distribution, endangering the mechanical properties of steel; angular type Ⅲ and type II exist in the same low-oxygen steel. Although ductile