ANSI AGMA 1010-F14-2014 Appearance of Gear Teeth - Terminology of Wear and Failure.pdf

1、ANSI/AGMA1010-F14 ANSI/AGMA 1010-F14 (Revision of ANSI/AGMA 1010-E95) American National Standard Appearance of Gear Teeth - Terminology of Wear and Failure AMERICAN NATIONAL STANDARD ANSI/AGMA 1010-F14 AGMA 2014 All rights reserved ii Appearance of Gear Teeth - Terminology of Wear and Failure ANSI/A

2、GMA 1010-F14 Revision of ANSI/AGMA 1010-E95 Approval of an American National Standard requires verification by ANSI that the requirements for due process, consensus and other criteria for approval have been met by the standards developer. Consensus is established when, in the judgment of the ANSI Bo

3、ard of Standards Review, substantial agreement has been reached by directly and materially affected interests. Substantial agreement means much more than a simple majority, but not necessarily unanimity. Consensus requires that all views and objections be considered, and that a concerted effort be m

4、ade toward their resolution. The use of American National Standards is completely voluntary; their existence does not in any respect preclude anyone, whether he has approved the standards or not, from manufacturing, marketing, purchasing or using products, processes or procedures not conforming to t

5、he standards. The American National Standards Institute does not develop standards and will in no circumstances give an interpretation of any American National Standard. Moreover, no person shall have the right or authority to issue an interpretation of an American National Standard in the name of t

6、he American National Standards Institute. Requests for interpretation of this standard should be addressed to the American Gear Manufacturers Association. CAUTION NOTICE: AGMA technical publications are subject to constant improvement, revision or withdrawal as dictated by experience. Any person who

7、 refers to any AGMA Technical Publication should be sure that the publication is the latest available from the Association on the subject matter. Tables or other self-supporting sections may be referenced. Citations should read: See ANSI/AGMA 1010-F14, Appearance of Gear Teeth - Terminology of Wear

8、and Failure, published by the American Gear Manufacturers Association, 1001 N. Fairfax Street, Suite 500, Alexandria, Virginia 22314, http:/www.agma.org. Approved August 8, 2014 ABSTRACT This nomenclature standard identifies and describes the classes of common gear failures and illustrates degrees o

9、f deterioration. Published by American Gear Manufacturers Association 1001 N. Fairfax Street, Suite 500, Alexandria, Virginia 22314 Copyright 2014 by American Gear Manufacturers Association All rights reserved. No part of this publication may be reproduced in any form, in an electronic retrieval sys

10、tem or otherwise, without prior written permission of the publisher. Printed in the United States of America ISBN: 978-1-61481-089-6 American National Standard AMERICAN NATIONAL STANDARD ANSI/AGMA 1010-F14 AGMA 2014 All rights reserved iii Contents Foreword vii 1 Scope . 1 2 Normative references . 1

11、 3 Definitions 1 3.1 Definitions 1 3.2 Classes and modes of failure 2 4 Wear . 3 4.1 Adhesion . 3 4.1.1 Mild adhesion 4 4.1.2 Moderate adhesion . 4 4.1.3 Summary of methods to reduce the risk of adhesive wear . 5 4.2 Abrasion 5 4.2.1 Mild abrasion . 5 4.2.2 Moderate abrasion 6 4.2.3 Severe abrasion

12、6 4.2.4 Sources of particles that may cause wear 8 4.2.5 Methods for reducing abrasive wear . 8 4.3 Polishing 9 4.3.1 Mild polishing . 9 4.3.2 Moderate polishing 9 4.3.3 Severe polishing 9 4.3.4 Summary of methods to reduce the risk of polishing wear . 10 4.4 Corrosion . 10 4.4.1 Methods to reduce t

13、he risk of corrosion 11 4.5 Fretting 12 4.5.1 True brinelling 12 4.5.2 False brinelling 13 4.5.3 Fretting corrosion 13 4.5.4 Summary of methods to reduce the risk of false brinelling and fretting corrosion 13 4.6 Scaling . 14 4.7 White layer flaking . 14 4.7.1 Summary of methods to reduce the risk o

14、f white layer flaking . 15 4.8 Cavitation 15 4.9 Erosion 17 4.10 Electric discharge 18 4.10.1 Summary of methods to reduce the risk of electrical discharge damage . 21 5 Scuffing 21 5.1 Mild scuffing 21 5.2 Moderate scuffing 21 5.3 Severe scuffing 23 5.3.1 Methods for reducing the risk of scuffing 2

15、5 5.3.2 Summary of methods to reduce the risk of scuffing 26 6 Plastic deformation 26 6.1 Indentation . 26 6.2 Cold flow 27 6.3 Hot flow . 27 6.4 Rolling . 27 AMERICAN NATIONAL STANDARD ANSI/AGMA 1010-F14 AGMA 2014 All rights reserved iv 6.5 Tooth hammer . 27 6.6 Rippling . 27 6.7 Ridging 30 6.8 Bur

16、r 30 6.9 Root fillet yielding 31 6.10 Tip-to-root interference 31 6.11 Tight mesh . 31 7 Hertzian fatigue 32 7.1 Macropitting . 32 7.1.1 Nonprogressive macropitting 32 7.1.2 Progressive macropitting . 34 7.1.3 Point-surface-origin macropitting 34 7.1.4 Spall macropitting 37 7.2 Micropitting 39 7.2.1

17、 Summary of methods to reduce the risk of micropitting 43 7.3 Subsurface initiated failures 44 7.3.1 Inclusion origin failures 44 7.3.2 Origins of nonmetallic inclusions . 44 7.4 Subcase fatigue. 45 7.4.1 Summary of methods to reduce the risk of subcase fatigue . 46 8 Cracking and other surface dama

18、ge 46 8.1 Hardening cracks 46 8.1.1 Thermal stresses . 47 8.1.2 Stress concentration . 47 8.1.3 Quench severity 47 8.1.4 Phase transformation 48 8.1.5 Steel grades 48 8.1.6 Part defects . 48 8.1.7 Heat treating practice 48 8.1.8 Tempering practice . 48 8.1.9 Summary of methods to reduce the risk of

19、hardening cracks . 48 8.2 Grinding damage . 49 8.2.1 Grinding cracks . 49 8.2.2 Overheating due to grinding 49 8.2.3 Summary of methods to reduce the risk of grinding cracks 50 8.3 Rim and web cracks 50 8.3.1 Summary of methods to reduce the risk of rim or web cracks 50 8.4 Case/core separation 52 8

20、.4.1 Summary of methods to reduce the risk of case/core separation . 54 8.5 Fatigue cracks . 54 9 Fracture 55 9.1 Brittle fracture 55 9.1.1 Methods for reducing the risk of brittle fracture . 58 9.2 Ductile fracture 58 9.3 Mixed mode fracture . 59 9.4 Tooth shear . 59 9.5 Fracture after plastic defo

21、rmation . 59 AMERICAN NATIONAL STANDARD ANSI/AGMA 1010-F14 AGMA 2014 All rights reserved v 10 Bending fatigue . 61 10.1 Low cycle fatigue . 62 10.2 High cycle fatigue 62 10.2.1 Morphology of fatigue fracture surfaces 63 10.2.2 Summary of methods to reduce the risk of high-cycle bending fatigue 64 10

22、.2.3 Root fillet cracks 65 10.2.4 Profile cracks . 65 10.2.5 Tooth end cracks . 66 10.2.6 Subsurface initiated bending fatigue cracks . 66 10.2.7 Tooth interior fatigue fracture, TIFF 73 Annexes Annex A Design considerations to reduce the chance of failure 75 Annex B Bibliography 79 Annex C Acknowle

23、dgements 81 Tables Table 1 - Nomenclature of gear failure modes 2 Table 2 - Failure modes that have subsurface origins 44 Table 3 - Fracture classifications 55 Table 4 - Differences between TIFF and subsurface initiated bending fatigue 74 Figures Figure 1 - Moderate wear 3 Figure 2 - Severe wear 4 F

24、igure 3 - SEM image - abrasion 6 Figure 4 - Mild abrasion near the tip of a ground gear 6 Figure 5 - Severe abrasion 7 Figure 6 - Severe abrasion, enlarged view of Figure 5 . 7 Figure 7 - Severe abrasion 7 Figure 8 - Severe polishing . 10 Figure 9 - Severe polishing . 10 Figure 10 - Extensive corros

25、ion 11 Figure 11 - Fretting corrosion 12 Figure 12 - Scaling 14 Figure 13 - White layer flaking 15 Figure 14 - Cavitation damage 16 Figure 15 - Cavitation damage 16 Figure 16 - SEM image - cavitation damage . 17 Figure 17 - SEM image - cavitation damage . 17 Figure 18 - Erosion of a high speed helic

26、al gear 18 Figure 19 - Electric discharge damage due to a small electric current . 19 Figure 20 - Severe electric discharge damage due to an electric current of high intensity 19 Figure 21 - SEM image - typical electric discharge crater 20 Figure 22 - SEM image - remelted metal and gas pockets near

27、edge of crater . 20 Figure 23 - SEM image - electric discharge damage 21 Figure 24 - Mild scuffing 22 Figure 25 - SEM image - scuffing damage showing rough, torn, and plastically deformed appearance 22 Figure 26 - SEM image - scuffing damage showing crater formed when welded material was torn from s

28、urface 23 Figure 27 - Moderate scuffing . 23 Figure 28 - Severe scuffing . 24 Figure 29 - Severe scuffing of a low speed gear lubricated with grease 24 Figure 30 - Severe indentations 27 Figure 31 - Hot flow . 28 Figure 32 - Plastic deformation by rolling 28 Figure 33 - Plastic deformation by tooth

29、hammer . 29 Figure 34 - Rippling . 29 AMERICAN NATIONAL STANDARD ANSI/AGMA 1010-F14 AGMA 2014 All rights reserved vi Figure 35 - Rippling . 29 Figure 36 - Rippling . 30 Figure 37 - Ridging 30 Figure 38 - Burr . 31 Figure 39 - Tip-to-root interference . 32 Figure 40 - Cross section through a tooth fl

30、ank showing how a pit develops below the surface . 32 Figure 41 - SEM image - pitting damage caused by Hertzian fatigue, showing fatigue cracks near boundary of pit 33 Figure 42 - Nonprogressive macropitting 33 Figure 43 - Progressive macropitting 34 Figure 44 - Point-surface-origin macropitting 34

31、Figure 45 - Point-surface-origin macropitting 35 Figure 46 - Point-surface-origin macropitting 35 Figure 47 - Point-surface-origin macropitting on carburized helical gear at 1.5 107cycles . 36 Figure 48 - Point-surface-origin macropitting on carburized helical gear at 3.0 107cycles . 36 Figure 49 -

32、Point-surface-origin macropitting on carburized helical driven pinion 37 Figure 50 - Point-surface-origin macropitting 37 Figure 51 - Spall macropitting . 38 Figure 52 - Micropitting on misaligned carburized gear 39 Figure 53 - Micropitting on induction hardened spur gear with crowned teeth . 39 Fig

33、ure 54 - Micropitting on nitrided and ground spur gear 40 Figure 55 - Detail of tooth surface showing micropitting . 40 Figure 56 - Detail of tooth surface showing micropitting at 1000X magnification . 41 Figure 57 - Regularly distributed micropitting . 41 Figure 58 - Subcase fatigue 45 Figure 59 -

34、Crack at a forging defect 46 Figure 60 - Hardening cracks 47 Figure 61 - Grinding cracks with a crazed pattern 49 Figure 62 - Rim crack 51 Figure 63 - Rim cracks in through hardened annulus gear . 51 Figure 64 - Fracture surface of rim crack shown in Figure 63 52 Figure 65 - Case/core separation . 5

35、2 Figure 66 - Case/core separation . 53 Figure 67 - Bending fatigue crack . 54 Figure 68 - Brittle fracture . 56 Figure 69 - SEM image of transgranular brittle fracture 56 Figure 70 - SEM image of intergranular brittle fracture . 57 Figure 71 - SEM image of ductile fracture 59 Figure 72 - Mixed mode

36、 fracture . 60 Figure 73 - Tooth shear . 60 Figure 74 - Fracture after plastic deformation . 61 Figure 75 - Two adjacent teeth on a helical pinion that failed by bending fatigue 63 Figure 76 - Bending fatigue of spiral bevel tooth 64 Figure 77 - Bending fatigue of two helical teeth 65 Figure 78 - Be

37、nding fatigue of several spur gear teeth . 66 Figure 79 - Bending fatigue of two bevel pinion teeth . 67 Figure 80 - Fatigue of several teeth that were loaded on both flanks . 68 Figure 81 - Profile cracks originating from severe pitting 69 Figure 82 - Broken tooth ends 69 Figure 83 - Bending fatigu

38、e initiation from subsurface nonmetallic inclusion . 70 Figure 84 - Bending fatigue due to nonmetallic inclusion . 70 Figure 85 - Fracture surface of loose fragment showing nonmetallic inclusion 71 Figure 86 - BSE image of fracture surface showing scanned areas 1, 2, and 3 71 Figure 87 - EDS spectru

39、m of figure 86 area 1 showing chemistry of the inclusion 72 Figure 88 - EDS spectrum of figure 86 area 3 showing chemistry of the steel matrix 72 Figure 89 - TIFF failure on an idler gear . 73 AMERICAN NATIONAL STANDARD ANSI/AGMA 1010-F14 AGMA 2014 All rights reserved vii Foreword The foreword, foot

40、notes and annexes, if any, in this document are provided for informational purposes only and are not to be construed as a part of ANSI/AGMA 1010-F14, Appearance of Gear Teeth - Terminology of Wear and Failure. This standard provides a means to describe the appearance of gear teeth when they wear or

41、fail. The study of gear tooth wear and failure has been hampered by the inability of two observers to describe the same phenomenon in terms that are adequate to assure uniform interpretation. The term “gear failure” is subjective and a source of considerable disagreement. For example, a person obser

42、ving gear teeth that have a bright, mirrorlike appearance may believe that the gears have “run-in” properly. However, another observer may believe that the gears have failed by polishing wear. Whether the gears should be considered failed or not depends on how much change from original condition is

43、tolerable. This standard provides a common language to describe gear wear and failure, and serves as a guide to uniformity and consistency in the use of that language. It describes the appearance of gear tooth failure modes and discusses their mechanisms, with the sole intent of facilitating identif

44、ication of gear wear and failure. The purpose of the standard is to improve communication between equipment users and gear manufacturers for failure and wear analysis. Since there may be many different causes for each type of gear tooth wear or failure, it is not possible in the standard to identify

45、 a single cause for each type of wear or failure, nor to prescribe remedies. AGMA Standard 110 was first published in 1943. A revised standard, AGMA 110.03, was published in 1979 with improved photographs and additional material. AGMA 110.04 was reaffirmed by the members in 1989. ANSI/AGMA 1010-E95

46、was a revision of AGMA 110.04. It was approved by the AGMA Membership in March 9, 1995. It was approved as an American National Standard on December 13, 1995. ANSI/AGMA 1010-F14 is a revision of ANSI/AGMA 1010-E95. It merges ANSI/AGMA 1010-E95 and AGMA 912-A04. New failure modes and additional photo

47、s were added and the content was reorganized. The description of failure mode morphology and mechanism was expanded, and methods to reduce the risk of a particular failure mode were added to the description of many of the failure modes. The first draft of ANSI/AGMA 1010-F14 was made in August, 2010.

48、 It was approved by the AGMA membership in June, 2014. It was approved as an American National Standard on August 8, 2014. Suggestions for improvement of this standard will be welcome. They may be submitted to techagma.org. AMERICAN NATIONAL STANDARD ANSI/AGMA 1010-F14 AGMA 2014 All rights reserved

49、viii PERSONNEL of the AGMA Nomenclature Committee Chairman: Dwight Smith . Cole Manufacturing Systems Vice Chairman: J.M. Rinaldo . Atlas Copco Comptec, LLC ACTIVE MEMBERS J.B. Amendola, III . Artec Machine Systems K. Burris Caterpillar, Inc. R.L. Errichello . Geartech O.A. LaBath Gear Consulting Services of Cincinnati, LLC M. Li Lufkin Industries, Inc. P. Terry . P. Terry however, many of the failure modes discussed may apply to gears made from other materials. The solution to many gear problems requires detailed investigation and analysis by specialists an