圆珠笔头用新型易切削不锈钢的组织与力学性能

Microstructure and Mechanical Properties of New Free-cutting Stainless Steels for Ball Pen Point

对圆珠笔头用新型高铬硫系铁素体易切削不锈铜冷拉线材的微观组织与力学性能进行了研究。结果表明，钢中易切削相为MnS、Pb及其与Te形成的复合夹杂物，均呈细小球状或椭球形沿拉拔方向断续、串链状分布。MnS夹杂物大小横向约1μm，纵向约10μm。钢中Cr、Mo的碳化物对改善MnS夹杂物形态有显著作用。该钢成品线材基体组织为细小铁素体晶粒，晶粒度约为10级，力学性能与进口同类钢线材相近，作为替代进口材料，其用于制造圆珠笔头，具有良好的切削性能，能满足生产加工和使用要求，填补了国内空白。

The microstructures and mechanical properties of cold pull wire of a new type ferritic free-cutting stainless steel used in ball pen with high-chromium and sulfur are studied. The results show that the free-cutting phases（inclusions） of the steels contain MnS,Pb and the composite inclusion consisting of MnS （or Pb） and Te. These free-cutting pha- ses are spherical or elliptical in shape,and distribute along with rolling direction of the steels in form of chains and intermittence. The transverse and lognitudinal size of the MnS inclusions is about 1μm and 10μm, respectively. The Cr carbide and Mo carbide in the steels play a remarkable role in improving shape of MnS inclusion. The finished-product wire of the steels has the ferrite matrix with the grain size of about grade 10,and the mechanical properties are similar to that of import steels for this usage. The steels can replace the import materials and have been used to fabricate ball-point of pens in industrial scale,which have good machinability and meet the requirements of the usage and filled in the domestic gaps.