自由锻都是以生产批量不大的锻件为主，采用锻锤、液压机等锻造设备对坯料进行成形加工，获得合格锻件。自由锻的基本工序包括镦粗、拔长、冲孔、切割、弯曲、扭转、错移及锻接等。自由锻采取的都是热锻方式。Freeforgingisintheproductionof***allquantitiesofforgings,theforging,hydraulicpressforgingequipmentiscarriedoutontheblankformingprocess,obtainqualifiedforgings.Thebasicprocessoffreeforgingincludingupsetting,stretching,punching,cutting,bending,torsion,displacementandweldingetc..Thefreeforgingisallhotforging.若因温度和变形程度选择不当而得到粗大晶粒时，可利用热处理相变细化晶粒***，但对于热处理中不发生相变的钢种，如奥氏体钢，就必须在锻造过程中获得细小而均匀的晶粒***，因此对这样的材料在锻造时须加倍注意。Ifthetemperatureanddegreeofdeformationandimproperselectionofcoarsegrains,thegrainrefinementphasechangeheattreatment,butforthesteelphasetransitiondoesnotoccurintheheattreatment,suchasausteniticsteel,itmustbeintheforgingprocessh***efineanduniformgrains,sothiskindofmaterialintheforgingmustpaymoreattentionto.碾环是指通过专用设备碾环机生产不同直径的环形零件，主要用来生产汽车轮毂、火车车轮等轮形零件。特种锻造包括辊锻、楔横轧、径向锻造、液态模锻等锻造方式，这些方式都比较适用于生产特殊形状的零件。Rollerringreferstotheproductionofcircularpartswithdifferentdiametersthroughtherollerringmachineofspecialequipment,whichismainlyusedtoproducewheelhub,trainwheelandotherwheelshapedparts.Specialforgingsincluderollforging,crosswedgerolling,radialforging,liquidforgingandsoon.Thesemethodsaresuitableforproducingpartswithspecialshape.随着电动机的发明，十九世纪末出现了以电为动力的机械压力机和空气锤，并获得迅速发展。直线往复锻造设备1、动载撞击的锻造设备2、动静载联合的锻造设备3，***能冲击的锻造设备。第二次以来，七十五万千牛的模锻水压机、一千五百千焦的对六万千牛的板料冲压压力机、十六万千牛的热模锻压力机等重型锻压机械，和一些自动冷镦机相继问世，形成了门类齐全的锻造机械体系。Withtheinventionofmotor,themechanicalpressandairhammerpoweredbyelectricityappearedattheendofnineteenthCentury,anddevelopedrapidly.SincetheSecondWorldWar,theforgingwaterpress,onethousandandfivehundredthousandchar,thepunchingpressofLiuWanqiancattle,thehotforgingpressofsixteenthousandthousandcattle,andsomeautomaticcoldheadingmachinesh***ecomeoutinsuccession,formingacompletesystemofforgingmachinery.)