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1 CARBODURCARBODURCARBODURE ngineering steelsCase-hardening steelsEDELSTAHL WITTEN-KREFELD GMBHCARBODURCARBODURCARBODUR3 ContentsPage 4 7 Carbodur The materialPage 8 9 Energy industryPage 10 11 TransportPage 12 13 General mechanical engineeringPage 14 15 Steel portraitsPage 16 17 Steel productionPage 18 19 Steel processingMaterial dataPage 20 31 Material Data Sheets(Please note the text on the flap of the rear cover, which containsinformation on the Material Data Sheets)Technical informationPage 32 36 HardenabilityPage 37 39 Machining and heat treatmentPage 40 43 Case-hardening treatmentPage 44 Overview of grades and chemical compositionPage 45 Melt analysis/International standardsPage 46 Forms suppliedPage 47 Hardness comparison tablePage 48 Temperature ComparisonPage 50 List of photosHow long a component stands upto demands, and how reliably itwithstands peak stresses, de-pends on the material the compo-nent is made of.

2 In the final analy-sis, the load-bearing capacity of asmall part determines the cost-efficiency of large machines more carefully the material istailored to the function of the re-spective components, the moreefficient the entire system WITTEN-KREFELD is thespecialist for producing high-grade steels with highly specific,precisely defined group of case-hardeningsteels marketed under the brandname Carbodur is evidence of theleading international position ofEdelstahl WITTEN-KREFELD in thefield of high-strength, case-hardening steels pre-sented in this brochure are un-alloyed and alloyed specialengineering steels with relativelylow carbon contents of to terms of non-metallic inclu-sions, the purity of these steels ishigher than that of normal qualitysteels.

3 They also respond moreuniformly to heat precise adjustment ofthe chemical composition and theuse of special production and testconditions, we are in a position tosupply you with steel gradesmanufactured with a wide varietyof processing and service proper-ties. Following carburising andhardening of the surface, case-hardening steels display greathardness and wear resistance inthe region of the surface layer,while the strength and toughnessof the base material are retainedin the case, tough core gets to grips5 Consequently, case-hardeningsteels or case-hardened compo-nents are indispensable whereverhigh wear resistance, high fatiguestrength and low notch sensitivityare choice of a steel grade isgoverned by the intended appli-cation.

4 The types of stress in-volved and the dimensions of theparts or the geometry of the com-ponents in question. Technicaland economic aspects are like-wise of decisive importance. Ourmaterials specialists are availablefor consulations concerning theoptimum choice and most expe-dient use of the various case-hardening steel unbeatable forhardness and durabilityCarbodurwith wear problemsmostly of a tensile nature, andthus increase the fatigue addition to their extraordinarywear resistance, componentsmade of Carbodur steels are thuscharacterised by very highstrength under dynamic loadsonce they have been , case-hardened compo-Maximum purityThe strength and toughness ofthe base material are determinedby its chemical composition andthe heat treatment it.

5 The required prop-erties of the steel are already spe-cifically targeted when first melt-ing the steel. The facilities inWitten and Krefeld permit a highlyaccurate and reliably repeatablechemical composition. An ex-tremely high degree of purity isachieved by the spot-on meltanalysis, secondary metallurgicaltreatment and vertical continuouscasting, or alternatively by remelt-ing. Non-metallic inclusions arevirtually ruled high degre of macroscopicand microscopic purity, thehomogeneity of the microstruc-ture and the fine-grain stability ofour Carbodur grades cannot bebeaten by any other manufacturerof high-grade hardenabilityThe selection of appropriate al-loying elements permits targetedcontrol of the hardenability of thebase material and the hardenabil-ity of the carburised surface addition to unalloyed case-hardening steels, we also offerthe following alloyed versions.

6 Manganese-chrome case-harden-ing steels, molybdenum-chromecase-hardening steels, nickel-chrome case-hardening steels,6nickel-chrome-molybdenum case-hardening steels and chrome-nickel-molybdenum case-harden-ing great hardness and thefatigue strength of the surfacelayer are achieved by the case-hardening treatment, by car-burising, hardening and temper-ing (or stress relieving). If, forexample, high strength is requiredin combination with high tough-ness of the core, the alloying ele-ments must be matched in such away that through-hardening isguaranteed at a given cross-sec-tion and with the given heat treat-ment.

7 This steel-specific through-hardening is offered by Carbodur,even at large are in a position to offer youcase-hardening steels manufac-tured specifically with the hard-ness you require. Make use ofthis opportunity - talk to ourmaterials specialists!High fine-grain stabilityThe targeted adjustment of thealuminium and nitrogen contentsof our Carbodur steels results inoutstanding fine-grain to this high fine-grain sta-bility, our steels are particularlysuitable for the direct hardeningof components, a process carriedout at high temperatures. Coarse-grain or mixed-grain steel wouldresult in non-uniform distortionand reduced rightHigh fatigue strengthInherent compression stressesarise in the surface layer whencase-hardening a stresses counteract theexternal stresses, which are7 Carbodur has just thechemstry for younents also have to demonstratethe highest possible ductilitywhen exposed to high dynamicstresses, in order to avoid brittlefractures.

8 As the impact strengthof the component decreases withincreasing case-hardening depth,the latter must not be too machinabilityThe larger the quantity of compo-nents to be manufactured, themore important the demand forgood machinability of the materi-al. This means that the economic efficiency of series production isalready defined when ordering thesteel. The machinability of case-hardening steels is influenced bythe microstructure, the strengthand the non-metallic inclusions (sulphides, oxides) that may bepresent. The machinability of thesteel can be further optimised byincreasing the amount of sulphid-ic inclusions, by calcium treat-ment and by appropriate heattreatment, by specifically ad-justing the heattreatmentDepending on the intended appli-cation and processing, we cansupply you with Carbodur steelgrades in a wide variety of treatedconditions, with reducedhardness, maximum hardness ora specific hardness range.

9 Treatedfor ferrite-pearlite structure or forspherical technical information onforms supplied and machiningcan be found from Page staying with Carbodur The world of Carbodur steels isthe world of drive systems. Theirstrengths are in demand whereverpower is transmitted. The indi-vidual components of the mightytransmission mechanisms used inhydroelectric power stations, windturbine generators or in the off-shore industry not only have towithstand enormous pressures perunit of area, they also have to runconstantly and untiringly. This callsfor wear resistance and fatiguestrength. Precision gear wheelsmade of Carbodur in the propellerdrives of drilling rigs and turbinegears of power stations reliablywithstand the stresses and, thanksto their wear resistance, reliablyguarantee the dimensional stabilityof the components.

10 Safety takestop priority in the mining underground extraction equip-ment essentially works non-stopwithout a break. Malfunctionsbrought about by the failure oftransmission components not onlymean expensive interruptions inproduction, but also increase thesafety , the emphasis is not so muchon resistance to impact and shockloads as on hardness and corestrength. Our chrome/nickel orchrome/nickel/molybdenum-alloyed Carbodur grades, for ex-ample, offer the best prerequisitesfor meeting the stringent require-ments. Our Carbodur 17 CrNi 6-6and Carbodur 18 Cr NiMo 7-6grades, for instance, are particu-larly suitable for relatively case-hardening steelsCarbodur takes more, lasts longerEnergy industry10 Carbodur the winnercomes Just as there is a wide variety ofdemands on the components fordifferent types of vehicle, we alsohave a wide variety of options forprecisely adapting our Carbodursteels to suit the prevaillign re-quirements.