• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    The invention relates to a method for enhancing fatigue durability of a conveyor belt (1) of a strand sintering furnace, and a conveyor belt. The conveyor belt is formed from a number of rectangular steel plate elements (2) that are sequentially welded to each other by weld seams (3) . Each plate element (2) includes a plurality of holes (4) arranged into a plurality of groups (5) of perforations to enable the flow-through of the gas used in the sintering process. The conveyor belt (1) is treated to create compressive residual stresses at a surface of the conveyor belt at least in critical regions which are susceptible to fatigue breakage. The conveyor belt (1) includes compressive residual stresses at a surface of the conveyor belt at least in critical regions which are susceptible to fatigue breakage. Thereby the fatigue durability of the conveyor belt is improved.(Figure 1)
    公开号:SE1550426A1
    申请号:SE1550426
    申请日:2013-10-07
    公开日:2015-04-09
    发明作者:Paavo Laihonen；Mari Lindgren
    申请人:Outotec Finland Oy；
    IPC主号:
    专利说明:

    lO METHOD FOR ENHANCING FATIGUE DURABILITY OF A CONVEYORBELT OF A STRAND SINTERING FURNACE, AND CONVEYOR BELT FIELD OF THE INVENTION The present invention relates to a method for enhanc-ing fatigue durability of a conveyor belt of a strandsintering furnace. Further, the present invention re-lates 1x> a conveyor belt (If a strand sintering fur- nâCG .
    BACKGROUND OF THE INVENTION Continuous strand sintering is used for agglomerizingpellets after pelletizing' a concentrate powder, im-proving the strength and the reactivity of the pel-lets.
    As an example of the strand sintering' technique, astrand sintering furnace could be mentioned, which isused in the production of ferro-chromium and dividedinto several sequential zones, different temperatureconditions prevailing in each one of them. The strandsintering equipment includes a conveyor belt, which isa perforated steel belt. It is conveyed as an endlessAt the forward end ofwet fresh pellets are fed onto the steel belt to form a pellet bed. loop around two deflector rolls.the furnace,The steel belt conveys theand sin- bed of pellets through the drying, heating, tering zones of the furnace and to a stabilizing orafter which the bed of pellets fur-After sintered equalizing zone,ther travels through sequential cooling zones.travelling through the the exit the cooling zones, pellets strand tail. sintering equipment at its in documents WO Ol/55659 Al and WO the conveyor belt of a strand sinter- As disclosed e.g.2009/022059 Al, ing furnace is formed. fron1 a number of rectangular lO steel plate elements that are sequentially welded toeach other by weld seams. Each plate element includes a plurality' of holes arranged into a plurality of groups of perforations to enable the flow-through ofthe gas used in the sintering process.
    During operation, the conveyor belts are subjected tostatic and dynamical loads, corrosive environment and elevated temperature. Dynamical loads, i.e. fatigue cause damage that commonly limits the lifetime(feg loads,of the belt.li lflê loads igue loads) Cyclic Lä: 'w C;ta '_ x. around t' deflector rollflo helt r. ates ed when raise"* tne _perfcrations act as stress -'- - ,- ß - - ~.D *så kl fi å). S in' tigue cracks are typically initiated. and start to grow. This especia'ly in the perfo" rated regions. Fatigue occurs when a material is sub- jected to repeated and unloading and at least part of the loading cycle is tensile, lf the loads are above a certain threshold, niçroscopic cracks will Eventnally a crack will surfalf; begin te form at reach a critical size, and the structure will suddenly «~-: Load related factors that inrrt _ _ '_ 1 .Cn s. < A .a . w _..“ i f.- kf L, ä: .-_ O. fracture. tigue life are for example stress amplitude and mean tress_ the load tensile part of cycle will cause C; fatigue as crack surfaces are torn open and the crack is able to proceed.made by Weldlsaded weld seam changes the geometry The conveyor belt is weldingo f x'_14 öIïLíÉ .ÉÛEÉ cyclically strnctures problematic in locally aid as a cons<~ quence act as a stress raiser. Additionally, tensile residual stresses generated and weld seam mi~ crostructure may not attain the properties of the basematerial.t <3 thod is ts onto repair'Ia but The current weld patches cracked area, it helps only temporarily as repair lO welding impairs the properties of the surrounding ma~ terial and causes distortions due to non~uniform heat~ ing. Consequene S the belt must be discarded and re~ placed, which limits the lifetime of the belt.OBJECT OF THE INVENTIONThe object of the invention is to eliminate the disad- vantages mentioned above.
    In particular, it is an object of the invention to provide a method by which the fatigue durability of aconveyor belt can be enhanced.
    Further, it is an object of the invention to provide aconveyor belt having a prolonged fatigue life and alonger lifetime.
    Further, it is an object of the invention to provide aconveyor belt in which the improved fatigue life canstainless steel be achieved with leaner (and cheaper) alloys.
    Further, it is an object of the invention to provide a method which may improve iield stress of the material oi the conveyor' belt, which may aileviate problems with local yielding.Further, it is an object of the invention to provide amethod which can be used for a new conveyor belt whileit is manufactured and also for existing conveyor belts which are already in use.
    SUMARY OF THE INVENTION According to an aspect of the invention, the presentinvention provides a method for enhancing fatigue du-rability of a conveyor belt of a strand sintering fur-formed. fron1 a number of nace. The conveyor belt is lO rectangular steel plate elements that are sequentiallywelded to each other by weld seams, each plate elementincluding a plurality of holes arranged into a plural-the flow- Ac- ity of groups of perforations to enablethrough of the gas used in the sintering process.cording to the invention, the conveyor belt is treatedto create compressive residual stresses at a surface ofthe conveyor belt at least in critical regions whichare susceptible to fatigue breakage.
    According to another aspect of the invention, the pre-sent invention provides a conveyor belt of a strandsintering furnace. The conveyor belt is formed from anumber of rectangular steel plate elements that aresequentially welded to each other by weld seams, eachplate element including a plurality of holes arrangedinto a plurality of groups of perforations to enablethe flow-through of the gas used in the sintering pro-cess. The conveyor belt includes compressive residual stresses at a surface of the conveyor belt at least in critical regions which are susceptible to fatiguebreakage.The invention makes it possible to prevent fatigue failures in the conveyor belt, thus prolonging its fa- tigue life. Further, the invention makes it possible to use leaner (and cheaper) stainless steel alloys forthe material of the belt and still gain a long fatiguelife. it Inay Further, an advantage of the invention is that stress of ïfiwfi material of the improve yield :onveyor belt, The method of the which may alleviate problems with local yielding. invention. can. be imple- mented to newly manufactured conveyor belts in connec-tion to their manufacturing process. The invention canas well be implemented to conveyor belts already in use to life of such belts. prolong the fatigue conveyor lO In one embodiment of the invention, in the method, theconveyor belt is treated to create compressive residualstresses at the surface of the conveyor belt at regionsof the groups of perforations.
    In one embodiment of the invention, in the method, theconveyor belt is treated to create compressive residualstresses at the surface of the conveyor belt in regions of the weld seams. in the method, thewhichis repeatedly subjected to In one embodiment of the invention,surface on the outer side of the conveyor belt,outer surface, in operation,tensile stress, is treated. to create the compressive residual stresses on the outer side of the conveyor belt.
    In one embodiment of the invention, in the method, thesurfaces of both sides of the conveyor belt are treatedon both to create the compressive residual stresses sides of the conveyor belt.
    In one embodiment of the invention, in the method, theconveyor belt is treated to create compressive residualstresses substantially only in the regions of groups ofperforations and in the regions of the weld seams while other areas of the conveyor are left untreated. the stresses is In one embodiment of the invention, in the method, treatment to create compressive residual chosen fron1 a group of treatment processes including shot peening, ultrasonic hammering, laser shock peen~ ing. Shot peening is a well-known cold working process used. to produce a compressive residual stress layer and modify mechanical properties of metals. It entails impacting a surface with shot (round metallic, glass, lO or ceramic particles) with a force sufficient to cre- ate plastic deformation. The plastic deformation in- duces a residual compressive stress in a peened sur- face, along with tensile stress of smaller magnitude in the interior. Surface compressive stresses confer resistance to metal fatigue and to some forms of stress corrosion cracking. The tensile stresses on thesurface are problematic because cracks tend to startUltrasonic is a well-known on the surface. hammering metallurgical processing technique, similar to work hardening, in which ultrasonic energy is applied to ametal object. The ultrasonic treatment can result incontrolled residual compressive stress, grain refine-ment and grain size reduction. Low and high cycle fa- tigue resistance are enhanced. Further, laser shockpeening is the process of hardening or peening metalusing a powerful laser. Laser peening can impart on asurface a layer of residual compressive stress that isfour times deeper than that attainable from conven-tional shot peening treatments.
    In one embodiment of the invention, in the method, theconveyor belt is treated in a flat form to create saidAfter the free ends of the conveyor belt are welded together by compressive residual stresses. treatment, an installation weld seam to form the conveyor belt in-to an endless loop form. the installationweld stresses in the region of the installation weld seam.
    Thereafter, seam. is treated. to create compressive residual In one embodiment of the invention, the conveyor beltincludes compressive residual stresses at the surfaceof the conveyor belt in the regions of the groups of the perforations. lO In one embodiment of the invention, the conveyor beltincludes compressive residual stresses at the surfaceof the conveyor belt in the regions of the weld seams.
    In one embodiment of the invention, the nmterial ofthe conveyor belt is chosen from stainless steel gradesincluding: ferritic chromium-alloyed stainless steel,austenitic-martensitic precipitation hardened stainlessaustenitic-ferritic steel, austenitic stainless steel, duplex stainless steel.
    In one embodiment of the invention, each plate elementcomprises two long edges in the lateral direction ofthe conveyor belt, which are parallel to and spacedfrom each other, the long edge of a similar adjacent second plate element being connected to each long edge, and two short edges in the longitudinal direc-tion of the conveyor belt, which are spaced from eachother by a distance corresponding to the width of theconveyor belt.
    In one embodiment of the invention, the groups of per-forations are rectangular and elongated, extending inthe direction of the conveyor belt, the groups of per-forations being parallel to each other and spaced fromeach other by a first imperforated area.
    In one embodiment of the invention, the groups of per-forations are subdivided into a number of subgroups ofperforations spaced from each other by a second imper- forated area.
    BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included to pro- vide a further understanding' of the invention and constitute a part of this specification, illustrate lO embodiments of the invention and together with the de-scription help to explain the principles of the inven-tion. In the drawings: Figure l is a plan view of a part of an embodiment of the conveyor belt according to the invention, Figure 2 shows the detail P of Figure l, Figure 3 schematically shows a cross-section. of theconveyor belt treated to include compressive residualstresses on its surfaces and the distribution of ten-sile and compressive stresses in a situation when noload is exerted, andFigure 4 shows the cross section of Figure 3 in a sit- uation when a bending load is exerted on the belt.
    DETAILED DESCRIPTION OF THE INVENTIONFigure l shows part of the conveyor belt l of a strandThe consists of a number of rectangular steel plate ele- sintering furnace (not shown). conveyor belt lments 2 that are sequentially welded to each other by weld seams 3.
    Each plate element 2 includes a plurality of holes 4arranged into a plurality of groups 5 of perforationsto enable the flow-through of the gas used in the sin-tering' process. The arrangement of the holes 4 intogroups 5 and subgroups 5' that disclosed in WO 2009/022059 Al. substantially corresponds to Each plate element 2 comprises two long edges 6, 7 inthe lateral direction y of the conveyor belt, whichare parallel with and spaced from each other. The long edge of a similar adjacent second. plate element is connected to each long edge 6, "7 by a weld seam 3.
    The two short edges 8, 9 are in the longitudinal di- rection x of the conveyor belt 1. The short edges areparallel and spaced from each other by a distance de-fining the width L of the conveyor belt. The groups 5of perforations are rectangular and elongated, extend-ing in the direction of the conveyor belt. The groups 5 of perforations are parallel to each other and spaced from each other by a first imperforated area10. The groups 5 of perforations are further subdivid-ed into a number of subgroups 5' of perforationsspaced from each other by a second imperforated area11.
    The outer side is of the conveyor belt 1 in its end- less loop form, in operation, is repeatedly subjected to tensile stresses as it turns around the deflectorrolls. Therefore at least the outer' surface of theconveyor belt 1 has been treated to induce compressiveresidual stresses at the outer side surface of the con-veyor belt at least in critical regions A and B which are susceptible to fatigue breakage.
    The critical regions are the regions A of the groups 5of the perforations and the regions B of the weld seams3. These regions A and B are schematically indicated in Figures 1 and 2 as areas enclosed by dot-and-dash lines. The compressive residual stresses at the sur- faces of the belt can be achieved by subjecting the regions A and B to shot peening, ultrasonic hammering or laser shock peening etc..The material of the conveyor belt 1 may preferably be ferritic stainless steel12), stainless steel, chromium-alloyed (e.g. 3Cr austenitic-martensitic precipitation hardenedaustenitic stainless steel or austen- itic-ferritic duplex stainless steel. lO In the perforated region Q, 5', the h » e act as ress local stress is : meaning sig~ nifieantly higher the applied stressi Weld seams 3; on the oth er hand, always have isile residu~ al streiie are caused by restricted t ermal ez~ pension weld seam during weld deposition and Cooling. By implementing the method of the invention, 1 weid can the harm al tensile residuel stresses in the be alleviated, or henefioial compressive a stresses can be created in the perfofated area, een he p olohged sienificantlv.a the e-t 1' reste” Wi h s“it^ble 1ffce^”e. :Ci-tiil ti. wifi: om... :l/lsfli-...Aycx shot peening, ultrasonic hammerinäf laser shook peen~ k: _4__5.Lflxïj , .J the underlying metal cohtra,ts the free movement of the surface, and compressive residual stresses are created on t“ surface. strates a cross~seotion of ich both figure § the conveyor belt opposite surfaces of the regionsof the groups 5 of perforations have been treated so asto create compressive residual stresses. Figure 3 showsa stress distribution inside the steel material of thebelt in the unloaded condition wherein the surfaces arein compression while the core is in tension to balanceout the forces as shown in Figure 3. shows the helt structure and the stress dis~load due Figure é tribu ion of Figure 3 under a result ig from the additive uombinatien of stresses ii hä. to hend loading and initial compressive residual stresses, as shown in Figure 4, the surface of the belt structure in compression even en the oonvex side (ugTuy side in igure 4) and fatigue failures do not occur.
    The center is tnder tensile stress and the eoneave aside (lower side in the Figure 4) is in etmnressiono side far The belt structure can he loaded until the is in tension, but this tensile stress would be lO stresses at ll than what it would be if the belt structure wastreated Y, include the compressive residnal the surfaoeso It is obvious to a person skilled in the art that with the advancement of technology, invention may be implemented in various ways. the basic idea of theThe in- vention and its embodiments are thus not limited to the examples described above; instead, they may vary within the scope of the claims.
    权利要求:
    Claims (15)
    [1] 1. l. A method for enhancing fatigue durability of a con- veyor* belt (l) of a strand sintering' furnace, saidconveyor belt being formed from a number of rectangu-that(3), including a plurality of holes (4) lar steel plate elements (2) are sequentially welded to each other by weld seams each plate el-ement (2) arrangedinto a plurality of groups (5) of perforations to ena-ble the flow-through of the gas used in the sinteringclia ra.ct:e:ri ze d treated to process,belt (l) isstresses at a surface of the conveyor belt at least inwhich in that the conveyor create compressive residual critical regions are susceptible to fatigue breakage.
    [2] 2. The method according to claim l, c:h alfa ct:e r - i z e d in. that the conveyor* belt (l) is treated. tocreate compressive residual stresses at the surface ofthe conveyor belt in regions of the groups (5) of per-forations.
    [3] 3. The method according to claim l or 2, clia reac - t e ri_z e<í in that the conveyor belt (l) is treatedto create compressive residual stresses at the surface of the conveyor belt in regions of the weld seams (3).
    [4] 4. The method according toin that the(1),is repeatedly subjected to tensile stress, any of claims l to 3,c h a r a c t e r i z e d surface on outerside of the conveyor belt which outer surface, inoperation,is treated to create the compressive residual stresses on the outer side of the conveyor belt.
    [5] 5. The method according toin that the any of claims l to 3,of both are treated to create c h a r a c t e r i z e d surfaces sides of the conveyor belt (l) lO l3 the compressive residual stresses on both sides of theconveyor belt.
    [6] 6. The method according' to any of claims l to 5,that the belt (l) is treated to create compressive residual stresses c h a r a c t e r i z e d in conveyor substantially only in the regions of groups of perfora-tions (5) (3), of the conveyor* belt are left un- and in the regions of the weld seamswhile other* areastreated.
    [7] 7. The method according' to any of claims l to 6,c h alfa ct:e ri_z e d in that the treatment to create compressive residual stresses is implemented. by shot hammerino laser shock peening, ultrasonic J, peening, etc..
    [8] 8. The method according' to any of claims l to 7,c h a r a c t e r i z e d in. that the conveyor* belt (l)is treated in a flat form to create said compressiveresidual stresses; the free ends of the conveyor beltare welded. together~ by' an installation. weld. seam. toform the conveyor belt into an endless loop form, and thereafter the installation weld seam. is treated tocreate compressive residual stresses in the region ofthe installation weld seam.
    [9] 9. A conveyor belt (l) of a strand sintering furnace,the conveyor belt being formed from a number of rec-tangular steel plate elements (2) that are sequential-(3), including a. plurality (If holes (4) ly welded to each other by weld seams each plate element (2) ar-ranged into a plurality of groups (5) of perforationsto enable the flow-through of the gas used in the sin-that the tering process, c h alfa ct:e ri_z e d in conveyor belt (l) includes compressive residual stress- 14 es at a surface of the conveyor belt at least in criti-cal regions which are susceptible to fatigue breakage.
    [10] 10. The conveyor belt according to claim 9, cl1a;r- a ct:e ri_z e<í in that the conveyor belt (1) includes at the surface of the of the compressive residual stressesconveyor belt in the regions of the groups (5) perforations.
    [11] 11. The conveyor belt according' to clain1 9 or 10, c h a r a c t e r i z e d in. that the conveyor* belt (1)includes compressive residual stresses at the surfaceof the conveyor belt in the regions of the weld seams (3).
    [12] 12. The conveyor belt according to any of claims 9 to11, c h alfa ct:e ri_z e<í in that the material of theconveyor belt (1) is chosen from stainless steel grades including: ferritic chromium-alloyed stainless steel, austenitic-martensitic precipitation hardened stainlessaustenitic-ferritic steel, austenitic stainless steel, duplex stainless steel.
    [13] 13. The conveyor belt according to any of claims 9 to12, clia re1c1:e ri_z e<í in that each plate element(2) comprises two long edges (6, 7) in the lateral di- rection (y) of the conveyor belt, which are parallel to and spaced from each other, the long edge of asimilar adjacent second plate element being connectedto each long edge (6, 7), and two short edges (8, 9)in the (x) of thebelt, corresponding to the width (L) longitudinal direction conveyorwhich are spaced from each other by a distance of the conveyor belt.
    [14] 14. The conveyor belt according to any of claims 9 to 13, clia ra.ct:e:ri ze d in that the groups (5) of perforations are rectangular and e1ongated, extendingin the direction of the conveyor belt, the groups (5) of perforations being para11e1 to each other and spaced from each other by a first imperforated area(10).
    [15] 15. The conveyor be1t according to c1aim 14, c11a;r-of perfora-(5')of perforations spaced from each other by a second im-(ll). a ct:e ri_z e d in. that the groups (5) tions are subdivided into a number of subgroups perforated area
    类似技术:
    公开号 | 公开日 | 专利标题
    SE1550426A1|2015-04-09|Method for enhancing fatigue durability of a conveyor belt of a beach sintering furnace, and conveyor belt
    KR20110060962A|2011-06-08|Pearlite rail
    RU2545855C1|2015-04-10|Method of reheating of rail welding zone
    US10786873B2|2020-09-29|Fillet arc welded joint and method for producing same
    JP6422575B2|2018-11-14|Method for intercooling thin steel sheets
    JPWO2010116680A1|2012-10-18|Rail welded portion cooling method, rail welded portion cooling device, and rail welded joint
    Kirihara2011|Production technology of wire rod for high tensile strength steel cord
    CN100560748C|2009-11-18|A kind of compounding method that prolongs the key elements of chain grate life-span
    CN100999781A|2007-07-18|High manganese steel frog surface explosive harden tech.
    CN109676227B|2020-12-29|900MPa high-strength loop chain pulse flash butt welding process
    US3345727A|1967-10-10|Method of making taper leaf springs
    EP0815325B1|2002-07-31|Improvements in and relating to steel rails and methods of producing the same
    Wen-jie et al.2018|The influential factors on very high cycle fatigue testing results
    SK282161B6|2001-11-06|Process and apparatus for heat-treating shaped rolled pieces and rolled profile
    JP5482559B2|2014-05-07|Bainite rail
    Muller et al.1981|The Influence of Shot Peening on the Fatigue and Corrosion Fatigue Behavior of an Austentic-Ferritic Stainless Steel
    JP3856536B2|2006-12-13|Crawler belt bushing and manufacturing method thereof
    JP6338953B2|2018-06-06|Special steel for sinter cake support stand
    CN105296727B|2019-06-21|The product as made of multiple Component compositions
    CN109623095B|2021-02-02|Isothermal welding bead method for high-hardness material repair welding
    RU2291040C1|2007-01-10|Method for roller restoring
    KR20160001572U|2016-05-13|Link chain using for continuous unloader
    Jeong2013|High-cycle fatigue properties of automobile cold-rolled steel sheet with stress variation
    USRE26714E|1969-11-18|Method of making taper leap springs
    CN106834912A|2017-06-13|A kind of wear-resistant railway switch cast steel preparation method
    同族专利:
    公开号 | 公开日
    CN104812685B|2017-03-08|
    EA028479B1|2017-11-30|
    CN104812685A|2015-07-29|
    EA201590513A1|2015-09-30|
    CA2885307C|2017-03-07|
    ZA201503137B|2016-01-27|
    CA2885307A1|2014-04-17|
    FI124911B|2015-03-31|
    WO2014057170A1|2014-04-17|
    FI20126061A|2014-04-10|
    BR112015007803A2|2017-07-04|
    AU2013328502A1|2015-04-02|
    AU2013328502B2|2016-04-21|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    JPS56139662A|1980-04-03|1981-10-31|Nisshin Steel Co Ltd|Metallic conveyor belt and its manufacture|
    FI111100B|2000-01-31|2003-05-30|Outokumpu Oy|Bands for continuous heat treatment of a material layer|
    US6651299B2|2000-10-13|2003-11-25|Toyota Jidosha Kabushiki Kaisha|Method and apparatus for manufacturing endless metallic belt, and the endless metallic belt manufactured by the method|
    JP2005508256A|2001-11-02|2005-03-31|ザ・ボーイング・カンパニー|Method and apparatus for forming a welded joint having a compressive residual stress pattern|
    CN1233501C|2002-05-22|2005-12-28|中国科学院金属研究所|Method of eliminating welding residual stress by low temperature compression deformation treatment|
    FI122006B|2007-08-15|2011-07-15|Outotec Oyj|Conveyor belt and method for repairing a conveyor belt|
    CN102601167A|2012-03-23|2012-07-25|天津大学|Ultrasonic shot blasting method for correcting weld buckling deformation of thin plate and application of ultrasonic shot blasting method|EP3405414A4|2016-01-19|2020-01-08|Laitram, LLC|Conveyor belt and module with skewed air-flow passages|
    AT520352A1|2017-08-24|2019-03-15|Berndorf Band Gmbh|Method for producing an endless belt with a band body comprising at least one sheet of duplex steel|
    DE102020103449A1|2020-02-11|2021-08-12|Bernd Münstermann Gmbh & Co. Kg|Plate conveyor belt for transporting a material web to be treated thermally by means of a gaseous temperature control medium and furnace with at least one plate conveyor belt|
    DE102020103452B3|2020-02-11|2021-04-22|Bernd Münstermann Gmbh & Co. Kg|Conveyor belt segment of a slat conveyor belt, slat conveyor belt and method for manufacturing a conveyor belt segment|
    法律状态:
    2018-06-05| NAV| Patent application has lapsed|
    优先权:
    申请号 | 申请日 | 专利标题
    FI20126061A|FI124911B|2012-10-09|2012-10-09|Method for raising the fatigue strength of a conveyor belt of a belt sintering furnace, and conveyor belt|
    PCT/FI2013/050971|WO2014057170A1|2012-10-09|2013-10-07|Method for enhancing fatigue durability of a conveyor belt of a strand sintering furnace, and conveyor belt|
    [返回顶部]