1、 Reference number ISO/TR 23602:2005(E) ISO 2005TECHNICAL REPORT ISO/TR 23602 First edition 2005-07-01 Toughness of chain steels Rsistance des aciers pour chanes ISO/TR 23602:2005(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes licensing policy, this file may
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6、9 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2005 All rights reservedISO/TR 23602:2005(E) ISO 2005 All rights reserved iiiContents Page Foreword. v 1 Scope 1 2 Normative references 1 3 Types of chain and extraction of specimens2 4 Materials, chemical composition and h
7、eat-treatment2 5 Tensile tests on chains .2 6 Conventional tensile tests on standard specimens.3 7 Notch impact tests.3 8 Fracture mechanics tests on notched chain links with slits.4 9 Fracture mechanics tests on notched three-point bend specimens with slits and fatigue cracks6 10 Correlation betwee
8、n the load-bearing capacity of chain links containing slits and material toughness.7 11 Fracture mechanics derivation of chain links 7 12 Load-bearing and brittle fracture transition concept Requirements.8 13 Correlation of test results with data from the literature 9 14 Summary.9 Figure 1 Results C
9、 vtests: Standard specimen (EN 10045)11 Figure 2 Load-time diagram for instrumented C v .13 Figure 3 Crack arrest load as function of temperature 14 Figure 4 Noncrystalline area in C v Test.15 Figure 5 LoadCOD diagram for TPB specimens with fatigue crack and eroded slits material type T, T = 40 C .1
10、6 Figure 6 LoadCOD diagram for TPB specimens with fatigue crack and eroded slits material grade VH, T = 40 C17 Figure 7 Comparison of pre-cracked and eroded chain link material grade VH, T = 40 C 18 Figure 8 Chain link specimen 19 Figure 9 Clip gauge fixed in chain link.20 Figure 10 Calibration of c
11、lip gauge for COD measurement.21 Figure 11 Test specimen at 40 C, three links.21 Figure 12 Effect of slit size on loadability of chain, T = 40 C .22 Figure 13 LoadCOD diagram for tension tests on chains with eroded slit, T = 40 C, a/d = 0,22.23 Figure 14 LoadCOD diagram for tension tests on chains w
12、ith eroded slit, T = 40 C, a/d = 0,43.24 Figure 15 LoadCOD diagram for tension tests on chains with eroded slit, T = 40 C, a/d = 0,64.25 Figure 16 Stable crack growth chain Type T, a/d = 0,22 Marked by heat tinting.26 Figure 17 Effect of slit size on absorbed energy of chains, T = 40 C 27 ISO/TR 236
13、02:2005(E) iv ISO 2005 All rights reservedFigure 18 Fracture mechanics tests on TPB specimens. 28 Figure 19 Fracture mechanics concepts. 29 Figure 20 Fracture toughness values for TPB specimens with eroded slits, T = 40 C, a/w = 0,5. 30 Figure 21 R-curves material Type T, T = 40 C, a/w = 0,4 . 31 Fi
14、gure 22 R-curves material Type T, T = 40 C, a/w = 0,4 . 32 Figure 23 Nominal fracture stress in chain link, correlated with fracture mechanics properties. 33 Figure 24 Nominal fracture stress in chain link correlated with fracture mechanics properties 34 Figure 25 Correlation of fracture load and C
15、vtoughness . 35 Figure 26 Correlation nominal fracture stress of chain and C vtoughness. 36 Figure 27 Finite element analysis of chain links with eroded slit, a/d = 0 37 Figure 28 Finite element analysis of chain links with eroded slit, a/d = 0,22. 37 Figure 29 Finite element analysis of chain links
16、 with eroded slit, a/d = 0,64. 38 Figure 30 Nominal stresses in cracked chain link . 39 Figure 31 Correction factor for long bending bars 540 Figure 32 Stress intensity factor for long bending bars . 41 Figure 33 Safety relations between requirement and service conditions . 42 Figure 34 Nominal frac
17、ture stress in chain link, correlated with fracture mechanics properties. 43 Figure 35 Correlation nominal fracture stress of chain and C vtoughness. 44 Figure 36 Correlation of fracture and C vtoughness pre-cracked TPB specimens 45 Table 1 Chemical composition of the chain steels 46 Table 2 Tensile
18、 test results on chain specimens (5 links) 46 Table 3 Tensile test results on standard specimens (EN 10002, B6*30) T = 40 C . 46 Table 4 Results of C vtests47 Table 5 Crack arrest loads of C vtests . 47 Table 6 Noncrystalline area of C vspecimens. 47 Table 7 Transition behaviour of chain materials 4
19、7 Table 8 Maximum loads of chain-tests at 40 C . 48 Table 9 Maximum displacement for chain tests, T = 40 C 48 Table 10 Absorbed energy of the chain tests, T = 40 C . 48 Table 11 Evaluation of fracture mechanics test on TPB specimens . 49 Table 12 Fracture mechanics tests on TPB specimens with eroded
20、 slits. 49 Table 13 Fracture mechanics tests on TPB specimens with fatigue cracks, T = 40 C . 49 Table 14 R curves data material Type T 50 Table 15 Calculation of K Qvalues for chain grade VH 50 Bibliography . 51 ISO/TR 23602:2005(E) ISO 2005 All rights reserved v Foreword ISO (the International Org
21、anization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been establi
22、shed has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardizatio
23、n. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting.
24、Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. In exceptional circumstances, when a technical committee has collected data of a different kind from that which is normally published as an International Standard (“state of the art”, for
25、 example), it may decide by a simple majority vote of its participating members to publish a Technical Report. A Technical Report is entirely informative in nature and does not have to be reviewed until the data it provides are considered to be no longer valid or useful. Attention is drawn to the po
26、ssibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO/TR 23602 was prepared by Technical Committee ISO/TC 111, Round steel link chains, chain slings, components and accessories, S
27、ubcommittee SC 1, Chains and chain slings. TECHNICAL REPORT ISO/TR 23602:2005(E) ISO 2005 All rights reserved 1 Toughness of chain steels 1 Scope The objective of the investigation presented in this Technical Report was to quantify the required material toughness for the operational safety of round
28、steel chains. The determination of this toughness must take place under unfavourable boundary conditions, i.e. at the lowest permissible operating temperature on damaged (precracked) chains. On the basis of characteristic properties determined on chains and three-point bend (TPB) specimens and the n
29、otch impact energy, a load-bearing and brittle fracture transition temperature concept was elaborated. From the correlation of the fracture stress of chains, fracture mechanics characteristic properties and the notch impact energy, minimum values of the notch impact energy can be derived which yield
30、 adequate safety against fracture for the damaged chain. Furthermore, in order to exclude brittle failure of chains, the position of the lowest permissible operating temperature relative to the NDT (nil-ductility transition) temperature was determined. Finally, the linkage of the determined fracture
31、 mechanics properties to notch impact energy values and the definition of the requirements for these values furnishes a simple test and acceptance procedure for chain materials and chain types. 2 Normative references The following referenced documents are indispensable for the application of this do
32、cument. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 3077:2001, Short-link chain for lifting purposes Grade T, (types T, DAT and DT), fine-tolerance hoist chain ISO 16872: 1) , Shor
33、t link chains for lifting purposes Grade VH, fine tolerance for manually operated chain hoists ISO 16877: 1) , Short link chains for lifting purposes Grade TH, fine tolerance for manually operated chain hoists DIN 17155, Steel for welded round links; technical delivery conditions EN 10083-3, Quenche
34、d and tempered steels Part 3: Technical delivery conditions for boron steels EN 10002 (all parts), Metallic materials Tensile testing EN 10045 (all parts), Metallic materials Charpy impact test BS 5762, Methods for Crack Opening Displacement (COD) Testing ASTM E 813, Standard Test for Jic, A Measure
35、 of Fracture Toughness ASTM E 399, Standard Test Method for Plane-Strain Fracture Toughness of Metallic Materials 1) Under preparation. ISO/TR 23602:2005(E) 2 ISO 2005 All rights reserved3 Types of chain and extraction of specimens For the investigation, chains of size 16 48 were selected. The diame
36、ter of 16 mm and the length of the straight shank are suitable for the extraction of notch impact bend and three-point bend specimens for fracture mechanics tests, as well as small standard tensile test specimens. For fracture mechanics tests of the chains themselves, the unwelded shank was notched
37、on the inner side. The test cross-section is thus the same for the chain specimen, the notch impact bend specimen and the standard tensile specimen which means that in all cases the testing is based on the same material and heat-treatment conditions. The 16 48 chains were manufactured to conform wit
38、h ISO 3077:2001, Type T, ISO 16877: 2) , Grade TH and ISO 16872: 2) , Grade VH. Thus chains which may be employed in all hoists (Type T) and exclusively in hand-operated hoists (Grade TH and Grade VH) are dealt with. Corresponding to their designation, the chains have a minimum nominal fracture stre
39、ss of 800 and 1000 N/mm 2 . 4 Materials, chemical composition and heat-treatment The materials requirements for the manufacture of the chains involved in the investigation are given in Table 1. Chains conforming to ISO 3077, Type T shall have the minimum contents given in Table 1 as regards the allo
40、ying elements Ni and Cr and/or Mo. Furthermore, the Al and the upper limits for P and S content are specified. For both chain types for use in hand operated hoists merely an Al content 0,025 and limits of P and S to 0,025 and 0,020 respectively are called for. In the lower part of Table 1, the produ
41、ct analyses for the individual chain specimens are given. A comparison with the specified values shows that all materials meet the requirements of the corresponding International Standard in every respect. For the material investigated for chains conforming to ISO 3077, a triple alloyed steel design
42、ated 23MnNiCrMo53 in DIN 17115 is invoked. The two chains of Types TH and VH were made of a manganese-boron steel of European manufacture. The steel is 19MnB4+Cr conforming to EN 10083-3. All of the chains investigated underwent an induction heat-treatment. They were austenitised inductively at 1 05
43、0 C and water quenched. Subsequently, conventional tempering took place in an air circulation furnace under the following conditions: ISO 3077:2001, Type T: 440 C/ 2 h ISO 16877: 2) , Grade TH: 365 C/ 2 h ISO 16872: 2) , Grade VH: 180 C/ 2 h 5 Tensile tests on chains The round steel chains selected
44、for the tests had not been subjected to the manufacturing proof force, by which the chains are stressed beyond their elastic limit such that in certain regions yield occurs and residual stresses arise. In subsequent tests, these residual stresses would have affected the determined material character
45、istic properties and especially their dependence on notch depth, in a manner which would not have been able to be understood. For this reason, the application of the manufacturing proof force was dispensed with. The tensile tests were carried out on the one hand at room temperature with 5-link speci
46、mens as in the corresponding chain standards and on the other hand at the lowest permissible operating temperature of 40 C. Since these low-temperature tests were carried out with the same gripping arrangements as with the fracture mechanics tests on notched and slit specimens, the testing was perfo
47、rmed at 40 C on 3-link specimens. This is of no importance, since the total ultimate elongation at fracture values is irrelevant due to the missing application of the manufacturing proof force. They were carried out nevertheless in order to obtain a starting point as to what deformation capacities t
48、he individual chains possessed. 2) Under preparation. ISO/TR 23602:2005(E) ISO 2005 All rights reserved 3 Table 2 gives the requirements for breaking force at room temperature in accordance with the appropriate standards and the fracture stress resulting therefrom as well as the requirements for tot
49、al ultimate elongation A. From this it can be seen that the requirements for fracture stress of chain to ISO 3077, Type T and chain to ISO 16877: 2) , Grade TH, are greater than 800 N/mm 2and for chain to ISO 16872: 1) , Grade VH, greater than 1 000 N/mm 2 . The required minimum total ultimate elongation values range from 10 % for the Type T chain to 17 % for the Grade VH chain
