EP0381648A1 - Méthode pour augmenter la résistance d'un élément utilisé pour le forage à percussion - Google Patents

Méthode pour augmenter la résistance d'un élément utilisé pour le forage à percussion Download PDF

Info

Publication number
EP0381648A1
EP0381648A1 EP90850025A EP90850025A EP0381648A1 EP 0381648 A1 EP0381648 A1 EP 0381648A1 EP 90850025 A EP90850025 A EP 90850025A EP 90850025 A EP90850025 A EP 90850025A EP 0381648 A1 EP0381648 A1 EP 0381648A1
Authority
EP
European Patent Office
Prior art keywords
deep rolling
deep
percussive drilling
rolling
strength
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP90850025A
Other languages
German (de)
English (en)
Inventor
Per Anders Rystedt
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sandvik AB
Original Assignee
Sandvik AB
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Sandvik AB filed Critical Sandvik AB
Publication of EP0381648A1 publication Critical patent/EP0381648A1/fr
Withdrawn legal-status Critical Current

Links

Images

Classifications

    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B10/00—Drill bits
    • E21B10/46—Drill bits characterised by wear resisting parts, e.g. diamond inserts
    • E21B10/56—Button-type inserts
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D7/00—Modifying the physical properties of iron or steel by deformation
    • C21D7/02—Modifying the physical properties of iron or steel by deformation by cold working
    • C21D7/04—Modifying the physical properties of iron or steel by deformation by cold working of the surface
    • C21D7/08—Modifying the physical properties of iron or steel by deformation by cold working of the surface by burnishing or the like

Definitions

  • the present invention refers to a method to improve the strength of an element for percussive drilling, said element being made of hardened steel and transferring impact energy in its axial direction, said method involving deep rolling of the surface layer of the element, at least in certain sections.
  • the invention also refers to an element worked in accordance with the method according to the invention.
  • fatigue the structural change is meant that arises due to the influence from a pulsating load and that eventually gives rise to a successively growing crack resulting in a fracture.
  • Fatigue is caused by strain hardening in connection with a complex dislocation motion and fatigue cracks are initiated in areas of very intensive dislocation motion. Such areas originate near notches and parts having sharp-edged corners etc. From this it is concluded that to a great extent fatigue cracks are initiated at the surface of the material.
  • the aim of the present invention is to remedy the negative influence that "poor" surfaces have upon the fatigue resistance.
  • Said aim of the present invention is realized by a method and an element that has been given the characteristics of the appending claims.
  • Figs.1-5 disclose how deep rolling is carried out;
  • Fig.6 discloses comparative surface sizing for different treatments;
  • Fig.7 shows how fatigue test of test pieces has been carried out; and
  • Fig.8 discloses a table of results from the fatigue test.
  • the characterizing feature of the invention is thus that the surface layer of elements for percussive drilling, at least in some "slim" sections, is subjected to deep rolling.
  • threads of drifter rods external surfaces of hexagonal rods and radii of down-the-hole bits may be mentioned.
  • the plastic working of the surface increases the fatigue strength.
  • Compression stresses in the surface result in that the resulting stress in the surface is reduced, i.e. the amplitude of the tensile stress decreases while the amplitude of the compression stress increases.
  • Cold working increases the hardness of the surface.
  • Cold working makes the surface notches less sharp-edged and evens out stress peaks in the bottom of the notches.
  • elements for percussive drilling refers to elements transferring impact energy in their axial direction.
  • Figs.1-3 For an extremely schematic illustration of deep rolling reference is being made to Figs.1-3.
  • an element 10 is worked by a rotating roller 11 under high pressure. This means that a rotation is imparted to the element 10 itself. This is indicated in Fig.1 and 2 by arrows of rotation 12 and 13. Normally a number of rolling laps of the element 10 are carried out.
  • the idea of the invention includes both deep rolling of the entire element 10 as well as deep rolling of only certain portions of the element 10.
  • the surface layer of e.g. a hexagonal rod no rotation of the rod is carried out but the rod itself is fed axially past a deep rolling roller.
  • Fig.4 it is shown what the distribution of compression stresses looks like in a deep rolled radius. The depth of the compression stresses can reach up to 4 mm and depends on rolling pressure, material, etc.
  • Fig.5 is shown more in detail how deep rolling is carried out.
  • the rotating roller is designated by 11 and the detail by 10.
  • the plastic working of the surface layer is provided by applying comparatively high forces - forces that exceed the yield point of the material - and thereby a plastic deformation occurs. Below the contact surface a wedge shaped zone is created. In said zone the condition of the material is changed. The surface layer is primarily compressed in subzone a and then it is plastified in subzone b and finally "flattened down" to a superfinish in subzone c as the contact is decreased and the stresses are reduced.
  • the main process is carried out in the area of the plastifying, whereby both the tops and the bottoms of the surface are plastified.
  • a rolling lap is required for a complete glazing of the surface.
  • the tops have in principle filled the bottoms in the metal cutted surface. This is however carried out in micro level and therefore no breaking down of coarseness tops occurs.
  • the originated contact area gets the above mentioned wedge shape having its terminating point directed in the feeding direction of the deep rolling roller.
  • the elongated feeding zone prevents the material from building up bulge-like at the end of the roller involving the risk of a thread-like waviness occurring on the surface of the part.
  • Fig.6 shows a turned surface. Both in shot peening and deep rolling one starts with a turned surface. Comparative tests have been made upon test pieces that through bending fatigue by 4-point load, se Fig.7, have been subjected to load changes, either to a fracture or until the number of load changes exceed 106. The test pieces have after turning either been untreated, shot peened or deep rolled. As is appearent from the table in Fig.8 significantly higher fatigue resistances are achieved for the deep rolled test pieces as compared to untreated and shot peened test pieces.
  • the present invention thus refers to deep rolling of elements for percussive drilling.
  • Said elements are made out of hardened, preferably case-hardened, steel.
  • the deep rolling gives rise to compression stresses to a depth of preferably at least 0.5 mm from the surface that is worked.
  • the residual stress (compression) of the element must preferably be > 0.5 ⁇ s .
  • the residual stress (compression) must be in the magnitude of 0.7-0.8 ⁇ s .
  • the surface finish that is achieved by the deep rolling must be ⁇ Ra 1.0.
  • roller burnishing is in principle equivalent with the above used deep rolling. However, there is usually the difference that in deep rolling higher forces are used within a more concentrated area of the element that is worked. No definite border line between the two methods exists but there is an overlapping zone. Throughout the present application the expression deep rolling has been used.
  • this subsequent treatment has the aim of further improving the surface finish of the elements.
  • this improvement of the surface finish is achieved by polishing or grinding.
  • Said surface finish is preferably in the magnitude of Ra 0.1.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Mining & Mineral Resources (AREA)
  • Mechanical Engineering (AREA)
  • Geology (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Organic Chemistry (AREA)
  • Metallurgy (AREA)
  • Environmental & Geological Engineering (AREA)
  • Fluid Mechanics (AREA)
  • Materials Engineering (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Earth Drilling (AREA)
  • Percussive Tools And Related Accessories (AREA)
  • Finish Polishing, Edge Sharpening, And Grinding By Specific Grinding Devices (AREA)
  • Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
EP90850025A 1989-02-02 1990-01-19 Méthode pour augmenter la résistance d'un élément utilisé pour le forage à percussion Withdrawn EP0381648A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SE8900358A SE8900358L (sv) 1989-02-02 1989-02-02 Foerfarande foer att aastadkomma haallfasthetsoekning hos ett element foer slaaende borrning
SE8900358 1989-02-02

Publications (1)

Publication Number Publication Date
EP0381648A1 true EP0381648A1 (fr) 1990-08-08

Family

ID=20374924

Family Applications (1)

Application Number Title Priority Date Filing Date
EP90850025A Withdrawn EP0381648A1 (fr) 1989-02-02 1990-01-19 Méthode pour augmenter la résistance d'un élément utilisé pour le forage à percussion

Country Status (7)

Country Link
EP (1) EP0381648A1 (fr)
JP (1) JPH02298478A (fr)
AU (1) AU4860790A (fr)
BR (1) BR9000355A (fr)
CA (1) CA2009179A1 (fr)
FI (1) FI900532A0 (fr)
SE (1) SE8900358L (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AT401630B (de) * 1992-05-25 1996-10-25 Plansee Tizit Gmbh Verfahren zur herstellung von formteilen mit gerollten flächen hoher passgenauigkeit
NL1023342C2 (nl) * 2003-05-05 2004-11-09 Skf Ab Werkwijze voor het behandelen van het oppervlak van een machineelement.

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3770595A (en) * 1970-11-23 1973-11-06 Stephanois Rech Method of treatment of steel parts in order to increase their resistance to wear and abrasion

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3770595A (en) * 1970-11-23 1973-11-06 Stephanois Rech Method of treatment of steel parts in order to increase their resistance to wear and abrasion

Non-Patent Citations (5)

* Cited by examiner, † Cited by third party
Title
MACHINES AND TOOLING, vol. 40, no. 1, 1969, pages 35-39; Y.G. SHNEIDER: "Classification of metal-burnishing methods and tools" *
METAL PROGRESS, vol. 118, no. 2, July 1980, page 51, Cleveland, US; "Surface roughness averages for common production methods" *
METAL SCIENCE AND HEAT TREATMENT, vol. 19, no. 7/8, 8th July 1977, pages 624-626; D.D. PAPSHEV et al.: "Formation of the hardened layer during burnishing of steel 55SM5FA" *
STAHL UND EISEN, vol. 104, no. 14, July 1984, pages 657-660, Düsseldorf, DE; E. VON FINCKENSTEIN et al.: "Eigenspannungen beim Oberflächen-Feinwalzen" *
TOOLING AND PRODUCTION, vol. 36, no. 10, January 1971, pages 37-38; "Burnishing that's really not" *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AT401630B (de) * 1992-05-25 1996-10-25 Plansee Tizit Gmbh Verfahren zur herstellung von formteilen mit gerollten flächen hoher passgenauigkeit
NL1023342C2 (nl) * 2003-05-05 2004-11-09 Skf Ab Werkwijze voor het behandelen van het oppervlak van een machineelement.

Also Published As

Publication number Publication date
BR9000355A (pt) 1990-12-04
AU4860790A (en) 1990-08-09
FI900532A0 (fi) 1990-02-02
SE8900358D0 (sv) 1989-02-02
SE8900358L (sv) 1990-08-03
JPH02298478A (ja) 1990-12-10
CA2009179A1 (fr) 1990-08-02

Similar Documents

Publication Publication Date Title
US8011096B2 (en) Methods for increasing the fatigue life, of crankshafts
GB2086295A (en) Method of prestressing the working surfaces of pressure chambers or cylinders
EP0925881B1 (fr) Outil
Shivalingappa The influence of ball and roller burnishing process parameters on surface integrity of Al 2024 alloy
KR100676333B1 (ko) 초음파 충격 처리에 의한 냉간 가공부의 강도 향상 방법 및파괴 인성 및 피로 강도가 높은 금속 제품
EP0381648A1 (fr) Méthode pour augmenter la résistance d'un élément utilisé pour le forage à percussion
Aftanaziv et al. IMPROVING RELIABILITY OF DRILL PIPE BY STRENGTHENING OF THREAD CONNECTIONS OF ITS ELEMENTS.
US7152699B2 (en) Connection rod and method for production thereof
CA2355129C (fr) Trepan a molettes ayant une resistance amelioree a la fissuration par fatigue
Brinksmeier et al. Superfinishing and grind-strengthening with elastic bonding system
Kirichek et al. Creating heterogeneous surface structures by static-pulsed treatment
SU1447645A1 (ru) Способ упрочнени трубчатых валов
EP1506321A1 (fr) Element de forage de roche et procede
Muller et al. The Influence of Shot Peening on the Fatigue and Corrosion Fatigue Behavior of an Austentic-Ferritic Stainless Steel
US20020079602A1 (en) Method of increasing the boundary layer strength on surfaces of workpieces made of brittle hard materials
US3938962A (en) Laminated composite wear materials
RU2126842C1 (ru) Способ упрочнения длинномерных цилиндрических изделий
KR20030076396A (ko) 중공강 육각 로드 및 그 고주파 담금질 방법
SU1310180A1 (ru) Способ поверхностного пластического деформировани цилиндрических деталей
RU2361058C2 (ru) Способ изготовления насосных штанг
CN206069939U (zh) 一种旋压刀具
AU783664B2 (en) Concrete reinforcement product
PL245108B1 (pl) Sposób wzmacniania przeciwzmęczeniowego trzonków noży styczno-obrotowych kombajnów górniczych
Misumi et al. Effect of Shot Peening on Fatigue Damage Curve
JPH10176241A (ja) 切断およびボルト孔加工の容易な高靱性高力ボルト接合スプライスプレート用鋼板およびこの鋼板を用いたスプライスプレート

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT DE FR GB SE

17P Request for examination filed

Effective date: 19901224

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 19930803