J.
KREÁK,
KREÁKP.etPETERKA,
al.: MECHANICAL TESTS OF THE STEEL WIRE ROPES AND STEEL WIRES
S. KROPUCH ISSN 0543-5846
METABK 43 (4) 345-347 (2004)
UDC - UDK 669-427:672.1:620.17=111
MECHANICAL TESTS OF THE STEEL WIRE ROPES AND STEEL WIRES
Received - Primljeno: 2004-02-20
Accepted - Prihvaæeno: 2004-06-20
Professional Paper - Strukovni rad
In the article we are dealing with the problems of the steel wires and steel wire ropes testing, which are very often
used today, and at the same time some negatives of the standards valid for steel wire rope testing are men-
tioned. In the article are mentioned also the drawbacks of new European standards which are implemented to
the system of Slovak technical standards. From the rope quality assessment point of view the lifting capacity of
the rope as a whole is important. In the article is briefly presented new shredder machine, with the maximum
shredding force of 2500 kN. The steel wire ropes with 63 mm in diameter and maximum length of 6 m can be
tested using this machine.
Key words: test of wire, test of the steel wire rope, bending test of wire, test machine
Mehanièka ispitivanja èeliènih uadi i èeliènih ica. U èlanku se raspravlja o problematici ispitivanja èeliènih
ica i uadi koja se danas vrlo èesto koriste, a jednovremeno se spominju i negativne karakteristike normi
vaeæih za testiranje èeliènog ueta. U èlanku su spomenuti i nedostaci novih evropskih standarda koji se uvode
u sistem slovaèkih tehnièkih normi. Sa stajalita procjene kakvoæe ueta, vaan je kapacitet dizanja u cjelini. U
èlanku je kratko prikazana nova kidalica s maksimalnom snagom kidanja od 2500 kN. Na tom stroju se mogu
ispitati èelièna uad promjera 63 mm i maksimalne duine 6 m.
Kljuène rijeèi: ispitivanje ice, ispitivanje èeliènog ueta, ispitivanje ice savijanjem, ispitni stroj
INTRODUCTION - test of number of twisting of individual wires,
- test of amount of zinc coating on individual wires.
Norms stating quality parameters present a follow up to
the norms containing methodical procedure of tests, and. Wires are most frequently tested according to DIN 2078
they specify exactly measuring devices and their equipment, or DIN 3051, or DIN 3078.
environment, personal qualification for a quality and failsafe
performance of individual tests. Quality result of ropes and At present wires are tested according to harmonized
wires tests is ensured by a quality manual, which presents a standards of the series STN EN 10264, but in Slovakia
control document of accredited test laboratories [1]. Ac- also according to appropriate non-harmonized STN.
credited test laboratories, besides quality test performance, At present in Slovakia there are the first four parts of
guaranty impartiality and confidentiality for a customer, to the STN EN 10264 standard proclaimed by SÚTN, which
which they are bound by the harmonized norm STN EN partially replaces above-mentioned standards. SÚTN has
ISO 17 025. The steel ropes and wires test can be conducted been preparing in years 2003 to 2004 the approval of a
on individual wires or on the whole [2 - 6]. Before making further standard (norm) (12 385), which will also be bind-
a rope by spinning individual wires producer carries out ing for steel rope test. These tests are carried out as con-
following: trol tests during work of a rope in authorized and accred-
- checking of diameters of individual wires, ited test floors [7 - 10].
- load carrying capacity test, (strength of individual wires),
- test of number of alternating bendings of individual TOTAL ROPE TEST
wires,
Total rope tests are carried out in manufacturer facilities
J. Kreák, P. Peterka, S. Kropuch, BERG Faculty Technical University in order to proclaim accordance, and in an independent test
Koice, Koice, Slovakia floor for the need of a rope certification. In this test both
METALURGIJA 43 (2004) 4, 345-347 345
J. KREÁK et al.: MECHANICAL TESTS OF THE STEEL WIRE ROPES AND STEEL WIRES
mechanical - elastic properties of a rope and its design and quality. On tear off machines it is possible to test also clamp-
correct lubrication of rope manifest themselves. Recently ing devices produced from steel ropes, chains, etc. and then
this test has been required quite often by rope users and in to assess their quality as a whole.
the norms of the 12 385 series has been mentioned as the
procedure number one. The test has been carried out on KNOWLEDGE GAINED
various test tear off presses. Tear off presses must fulfill the IN DESTRUCTIVE TESTS OF STEEL ROPES
requirements of the Act N0. 142/00 Coll. of L. and Regula-
tion N0.210/00 on Metrology. In our accredited steel rope By means of destructive tests of ropes and wires a manu-
test lab a new tear off machine KREPET BME/SKTC147 facturer or a test floor can proclaim that a rope has been
has been in operation, whose maximum tearing power is manufactured in desired quality as required by a relevant
2500 kN. The basic design of this machine is illustrated in standard according to which tests have been conducted.
Figure 1. The test sample of a rope is fixed in jaws of the From deficiencies found in tests [7], in our test floor
machine by means of pouring the ends of the sample with we consider the weightiest discord of STN 02 4301 with
STN 42 0421 for conducting test by alternating bending.
STN 42 0421 includes requirements similarly as DIN and
ISO standards, but STN 02 4301 does not include these
requirements.
The diameter of the bending roll stated by the standard
STN 02 4301 for and interval of wires diameter is differ-
ent than the one stated by the standard STN 42 0421.
A very serious deficiency of all standards (norms), e.g.
also international standards is the fact that the test by twist-
ing and alternating bending provide only minimum limit
of number of twists and bends which individual wires have
to sustain. Based on our experiences we suggest amend-
ing the numbers of twists and bends for the upper limit,
which should not be overcome by the wire after passing
the test with that number of twists and bends. The previ-
ous assertion results from the experience, which we gained
with the test of rope of the tow H 130 at which all tested
parameters complied with the relevant STN but the num-
bers of twists and bends reached up to the double amount
of that stated by the norm.
By more detailed examination it was found that though
the rope complied with STN 4301,on the wires there were
visible pressings caused by the carrier, which pointed out
at soft surface of the wires [5]. By metallographic and
fractographic tests it was proved that the wires, especially
their surface, were decarburated which caused enormous
Figure 1. Bearing structure of the tear off machine KREPET-BME prolongation of the rope, diminishing its diameter and cross
2500/SKTC147 section under the permitted limit and in the end its quick
Slika 1. Izvlaèna konstrukcija stroja KREPET-BME 2500/SKTC
147 impairment. Even though this given example is rare
(unique) it would be advisable that our standards consid-
liquid metal in taper endings. At present the Slovak branch ered also these cases.
standard, determining technological procedure of pouring
endings, is not valid. In pouring the endings the procedure CONCLUSION
is frequently carried out by former or current ÈSN, which
makes it possible to pour the sample endings by resin (bitu- Based on our experiences it can be stated that destruc-
men) in a taper ending. The test is ended by tearing off one tive tests of wires and ropes confirm the validity of con-
strand of the rope. In tearing off the power is recorded which clusions given in literature, that the smallest the interval
is then given as real load bearing capacity of a rope. The of scattering of mechanical-elastic properties of its wires,
real load carrying capacity of a rope characterizes its real especially load bearing capacity, the higher the quality of
346 METALURGIJA 43 (2004) 4, 345-347
J. KREÁK et al.: MECHANICAL TESTS OF THE STEEL WIRE ROPES AND STEEL WIRES
the rope. Recommended scattering is ± 5 % from the me- [4] J. Fries: Maintenance of long wall shearer, Diago, TU Ostrava,
dium measured load bearing capacity of wires [1]. The (2000).
[5] S. Kropuch, P. Peterka, J. Kreak: Magnetizaèné procesy poèas
fulfillment of this requirement guaranties even loading of defektoskopickej kontroly oce¾ových lán, Acta Metallurgica
individual wires of a rope in cross section and influences Slovaca, 9 (2003) 2, 122 - 130.
the prolongation of service life of a steel rope. [6] P. Peterka, J. Kreák, S. Kropuch: Skúsenosti z defektoskopických
kontrol oce¾ových lán v naftovom a plynárenskom priemysle, NDT
Buletin Welding, Betis s.r.o. Praha Bìchovice, 2 (2002), 21 - 23.
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ternal diagnostics of pipelines and its development at SOL SKTC-
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kontrol oce¾ových lán, NDT Buletin Welding, Betis s.r.o. Praha matica 2 (2002) 3, 92 - 95.
Bìchovice, 4 (2001), 78 - 80. [8] P. Peterka, J. Kreak, S. Kropuch: Diagnostika nadzemne vedených
[2] J. Boroka, J. Kreák, P. Peterka: Hodnotenie kvality oce¾ových plynovodných potrubí, SLOVGAS, 12 (2003) 6, 21 - 22.
lán z h¾adiska ich mechanických vlastností, Acta montanistica [9] E. Stroffek, I. Leo: Acoustic method for measurement of Young
slovaca, 2 (1997) 1, 37 - 42. modul of steel wire ropes, Metalurgija 39 (2000) 3, 216 - 218.
[3] J. Fries: Technická diagnostika na hlubinných dolech, Diago, TU [10] E. Stroffek, I. Leo: Acoustic method for measurment of Youngs
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