【作者】 高佩；

【导师】 陈康敏；

【作者基本信息】 江苏大学 ， 材料学， 2009， 硕士

【摘要】 目前,我国已成为世界制笔业生产和出口大国,但并不是制笔强国。在各类笔中圆珠笔的产量最大,且大多属中低档类,高档产品与国外差距较大,其关键因素是笔头质量,即笔头的结构、加工质量问题。圆珠笔头结构复杂,机加工均在全自动生产线上进行,生产加工工序多,切削速度快,装配和加工尺寸精度高,因此,要求圆珠笔头用材料应具备高速易切削、切屑碎、加工表面光洁度高,且对刀具磨损少等性能。目前,高档圆珠笔头材料主要采用易切削不锈钢,国内研究及生产甚少,基本依赖进口,因此开发研究圆珠笔头用易切削不锈钢显得十分迫切和必要。针对上述情况,通过研究国内、外相关试验成果,与南京金联安冶金机电有限公司共同合作开发了一种新型的用于圆珠笔头材料用的硫一铅复合铁素体易切削不锈钢。本文对此新型的圆珠笔头用易切削不锈钢(以下简称试验用钢)的中频炉+电渣重熔冶炼、热加工及成品线材加工工艺作了比较详细的概述,采用多种测试分析手段,重点研究了其冶炼、热加工工艺,易切削相形态特征、微观组织、力学性能及其切削性能,揭示其夹杂物特征(种类、形貌、尺寸、数量及分布)及对钢性能(切削性能、切屑形貌、表面粗糙度等)的影响,阐明钢的冶炼、加工工艺—夹杂物形态特征—性能三者间的关系,从而提出了优化的加工工艺。试验结果表明:试验用钢中易切削相主要为MnS、Pb、Te相。熔炼后热轧棒材中MnS夹杂物细小、呈椭圆形均匀分布,在冷拉成线材后横向上则呈椭圆形,纵向呈串链状沿钢轧制方向断续分布。Pb、Te及其混和物相呈细小颗粒状分布于钢基体中,或分布在MnS两侧。钢中的Cr、Mo碳化物脆性相,与MnS夹杂物共生,在轧制过程中被破碎,呈串链状、断续分布,对改善硫化物的形态有重要作用,且有利于提高钢基体的强度。S-Pb复合添加易切削不锈钢比单独添加S系易切削不锈钢及SUS 304不锈钢有更好的切削性能,可选用较高的切削用量,提高生产率。该钢冷拉线材的组织与进口SF20T钢线材相比夹杂物更细小、数量更多、分布更均匀,且性能接近,具有良好的组织形态和易切削性能,经实际试生产使用,各项性能均能满足生产和使用要求,基本达到国外进口同类钢材的水平。该钢属于特殊易切削不锈钢,除用于圆珠笔头材料外,还可用于仪器仪表、有耐腐蚀性和无磁要求的零件、各种喷嘴以及其他要求高加工精度、高切削加工性零部件等,具有良好的市场应用前景。更多还原

【Abstract】 At present,our country has become the world’s production and export country in pens manufacture,but it is not powerful.The yield of the ball-point pen that are middle and low grade are the greatest in various types of pens of our country,and most of the high ball-point pen that have a large gap with foreign ball-point pen,the key factor is the quality of ball-poin,that is the ball point structure,processing quality.The structure of ball-point pen is complex,and the machining are carried out in fully automated production lines,and production processes are numerous,and cutting speed is fast,and the accuracy of assembly and processing is high,therefore,it must have properties that are high free-cutting,broken chip,high surface finish and less tool wear for the ball-point pen material.At present,it mainly use free-cutting stainless steel for high-grade ball-point pen material,which is research and producted very little in domestic and mainly depend on imports,and therefore it is urgent and necessary to research and develop free-cutting stainless steel for ball-point pen.This article,in view of this situation,a new type of S-Pb free-cutting ferritic stainless steel for ball-point pen by researched and developed by Nanjing Jinlianan metallurgial and electromechanical Ltd and us through studying the domestic and foreign test results and combined with knowledge of the principles.In this paper,the intermediate frequency furnace and ESR smelting,hot maching, and cold maching technology of a new type of free-cutting stainless steel for ball-point pen were sumarized detailedly.a variety of test and analysis means were used to research the smelting and maching technics,and reveal the influence of the steel performance(cutting performance,chip morphology,surface coarseness grade,etc.) to different inclusions charicteristic(type,morphology,size,amout and distributing),and illustrate the relation between steel smelting,processing technology,inclusion morphology,and performance,and thereby the optimized maching technology were put forward.The test showed that the free-cutting phase of tested steel are mainly MnS,Pb,and Te phase.MnS inclusions in hot rolled bar are small and oval,and distribute uniformly. After hot machining the horizontal MnS inclusion of the free-cutting stainless steel are oval,and vertical MnS inclusion have a discontinuous distributin along with rolling direction of the steels by the form of chains.Pb,Te and its mixture phase are small granules and disturibute in steel matrix or on both sides of MnS.The Cr and Mo carbide phase in the steel is brittle,and coexist with MnS,they are broken and have a discontinuous distributin along with rolling direction of the steels by the form of chains, which is important to improve inclusion morphology and the strength of steel matrix. The cutting performance of the S-Pb free-cutting stainless steel better than the S free-cutting stainless steel and SUS 304 stainless steel,and the bigger cutting dosage can be choosed and producticity are advanced.The microstructure of the tested steel wire rod are smaller and more evenly distributed and more than the SF20T steel wire rod which is imported,and their performance are dosed,and they have good microstructure and free-cutting performance,and their performance can be meet the requiement of production and use,and achieve the level of foreign steels.The tested steel is a special free-cutting steel,which is used for ball-point pen,and instrument,the part have a high corrosion resistance and nonmagnetic,and high maching precision and high maching performance,etc.So it have a good market prospect to research and develop the free-cutting stainless steel for ball-point pen.更多还原