上锐紧固件生产工艺

1、紧固件制造Surface TreatmentHeat TreatmentThread RollingCold Head/Hot ForgingRaw MaterialPackingInspectionFastener Manufacture ProcessWithout machiningRaw MaterialRaw MaterialDesignated area for different types of steelTypes of steel indicated by colourRaw MaterialTags showing:- The manufacturer- The heat

2、 number- The dimension- The weight- The Carbon contentRaw MaterialWire Material Control:- Wire diameter- General aspect- Hardness- Hardenability- UTS- DecarbonRaw MaterialRaw MaterialPhosphating bathRaw MaterialBaths controlRegular cleaningPhosphated wiresWire calibrationRaw MaterialCold Heading/Hot

3、 ForgingHex Head Cap Screw Forging Sequence 4 StnCUT OFF STN1ST STN2ND STN3RD STN4TH STNCold HeadingCold HeadingCold HeadingCold HeadingIn process controlCold HeadingHot ForgingHot forgingBars heatingHot ForgingHot ForgingOver 25 mm DiameterThread RollingTHREADS ROLLINGA PROCESS OF FORMING THREADS W

4、ITHOUT REMOVING THE MATERIALFLAT THREAD ROLLINGPLANETRYY THREAD ROLLINGCIRCULAR THREAD ROLLINGSEGMENTAL CIRCULAR THREAD ROLLINGThread Rolling1 Flat rolling dies2 Segmental rotary rolling dies 3 Two rolls one supporting ledge4 Three rolls Thread RollingFLAT THREAD ROLLINGSTATIONARY DIEMOVING DIEBEFOR

5、EAFTERFor moderate production, CG 1,2,4 (partly),5,9,10 & 11,1290 % products from catalogueThread RollingCIRCULAR THREAD ROLLINGCIRCULAR ROLLING DIE 2 NOS.Low production rate, suitable for Odd head shape CG 4 (e.g. BN 253,256,276,278,258 & above M24 & critical auto parts)Thread RollingThread rolling

6、 after heat treatmentHorizontal thread rolling is mainly used to form thread after heattreatment, process is very precise but slow and not fit for large quantitiesThread RollingSEGMENTAL CIRCULAR THREAD ROLLINGCIRCULAR ROLLING DIE 2 NOS.STATIONARY DIEROTATING DIE3 TO 4 PIECES AT A TIMEFor M/c screws

7、, CG 5Thread RollingPlanetary Thread rollingThread rolling Set up thread rolling:5 samples are checked by QCIn-process control5 samples/15 mn (No record)Recorded values: every 1 hour (min-max)Heat TreatmentLPSHEAT TREATMENTA COMBINATION OF HEATING & COOLING OPERATIONS TO OBTAIN DESIRED PROPERTIESHAR

8、DENING HEATING & QUENCHINGTEMPERINGHeat TreatmentHEATINGHEATING THE MATERIAL ABOVE AUSTENISATION TEMPERATURE & SOAKING AS PER CROSS SECTIONQUENCHINGRAPID COOLING OF AUSTENISED MATL.?IMMERSING IN OIL OR WATERMARTENSITIC TRANSFORMATION RESULTING INTO INTERNAL STRESSESHeat TreatmentFor 8.8 and above 82

9、0 to 900 Degree CLPSTEMPERINGHeating Hardened material to specific temp. much below austenisation temp. for specific desired properties?Immediately after QuenchingREDUCES INTERNAL STRESSES & ALSO REDUCES HARDNESSHEAT TREATMENT PROCESS FOR 8.8 & ABOVE45010 Degree CFasteners of various grades made out

10、 of different steelsAt room temp. the Material is in Pearlite (Lamellar)/Spherodised & ferrite formQuenching Fast CoolingHard Martensite (accicular) Structure, Brittle, not suitable for useTemperingTempered Martensite Structure, product suitable for useFurnace Having three zones, Controlled atmosphere of endo Gas available from gas generator,cracked gas (LPG: Air: 1:10)Heati