高速钢软化新工艺开发

南京工程学院毕业设计说明书(论文)作者：张宸来学号：205060832系部：材料工程学院专业：金属材料工程题目：高速钢软化新工艺开发指导者：蔡璐副教授(姓名)(专业技术职务)评阅者：(姓名)(专业技术职务)2010年6月南京毕业设计说明书（论文）中文摘要W18G4V钢中合金元素含量很高，特别是钨的含量高达18%，钢中合金碳化物的数量很多且不均匀性较严重。合金碳化物在正常的热处理温度下不能完全溶解到奥氏体中去，因此不能靠正常的热处理方法来使碳化物分布均匀，只有通过锻，轧等压力加工的方法，才能将粗大的碳化物击碎，使其分布均匀。锻造后的毛胚硬度很高，一般在60HRC以上，无法进行机械加工，所以需要采用软化工艺。传统的软化工艺主要为等温球化退火，工艺周期较长，能源消耗大。通过对几个新型的软化工艺的尝试，包括水瀑退火，循环球化退火，水退火，高温回火等四个工艺，对组织和硬度分析，确定了采用循环退火工艺，硬度可以降低到30HRC左右，能很好地进行切屑加工，同时可以有效的缩短热处理时间。关键词W18G?4V钢；新工艺；软化；组织；硬度为降低高速钢的硬度，在切削加工前要进行软化处理。传统的软化工艺主要为等温球化退火，工艺周期较长，能源消耗大。本课题力求通过对新型的软化工艺的尝试，确定节能优化工艺。为此进行了水瀑退火，循环球化退火，水退火，高温回火四个工艺的试验研究，对各种工艺的组织和硬度进行了分析。试验结果表明：最佳软化工艺为高温回火，新工艺与传统工艺相比周期缩短……，其组织和硬度都可以达到加工要求。循环退火同样能够满足要求，在设备允许的条件下，具有较好的应用价值。毕业设计说明书（论文）外文摘要TitleW18G4VsteeltosoftenthedevelopmentofnewtechnologyAbstractThereishighcontentofalloyingelementsinW18G4Vsteel,Inparticular,tungstencontentofupto18%.Carbidealloysteelandunevennumberofmuchmoreseriousnature.Carbidealloyheattreatmenttemperatureinthenormalcannotbecompletelydissolvedintotheaustenitetogo,socannotrelyonthenormalheattreatmenttomakethecarbondistributionisonlythroughforging,rollingandprocessingmethodssuchaspressure,canbecoarsecarbidecrushed,sothatdistribution.Blanksafterforgingisveryhard,generallymorethan60HRC,cannotbemachined,sotheyneedbysofteningprocess.Softeningprocessismainlythetraditionalisothermalannealing,longerprocesscycle,energyconsumption.Throughthesofteningprocessofseveralnewattempts,includingtheCascadeannealing,cyclicannealing,water,annealing,temperingthefourprocessesoftheorganizationandhardnessweredeterminedbycyclicannealingprocess,thehardnesscanbereducedto30HRCso,canwellbethechipprocessing,andcaneffectivelyshortenthetreatmenttime.KeywordsW18G4Vsteel;newtechnology;softening南京工程学院毕业设计说明书（论文）目录第一章绪论......................................................................................................................21.1W18Cr4V钢的性能特点...............................................................................................21.1.1化学成分特点......................................................................................................21.1.2组织结构特点......................................................................................................31.1.3W18Gr4V钢退火过程中的组织转变................................................................31.2W18Gr4V钢软化传统工艺..........................................................................................31.2.1等温球化退火.....................................................................................................31.2.2目前存在的问题..................................................................................................41.3W18Gr4V钢软化新工艺..............................................................................................41.3.1循环球化退火工艺..............................................................................................51.3.2水退火法..............................................................................................................51.3.3水瀑退火..............................................................................................................51.3.4高速钢快速退火工艺..........................................................................................51.3.5高速钢高温回火工艺..........................................................................................51.4.钢的软化机理................................................................................................................61.4.1铁素体基体相的软化.........................................................................................61.4.2粗化碳化物颗粒，降低退火硬度......................................................................61.5硬度与切削性能............................................................................................................71.5.1易切削机理..........................................................................................................71.5.2组织与切削.........................................................................................................71.5.3硬度与切削..........................................................................................................8第二章实验材料和实验方法......................................................................................102.1实验材料......................................................................................................................102.2实验方案......................................................................................................................102.3实验设备......................................................................................................................11第三章新工艺开发研究..................................................................................................123.1新工艺研究.................................................................................................................123.1.1循环球化退火工艺............................................................................................123.1.2水退火工艺.......................................................................................................