bluuebunny/crossref_metadata_2025_split huggingface dataset:
Galvanized Cable Damaged by Localized Heating
Authors: Waldl Elfriede 
Published: May 2019

Abstract
Two sections of a galvanized cable 10.5 A 160 GR +NORM M 9533 (round stranded cable of normal type, h + 6, Langslay, right-handed) were examined. One had a 100 mm long blackish-brown tarnished zone obviously caused by localized heating at one end, inside which the hemp core was missing, and the other corresponded to the original condition of the cable. The cause of the damage was unknown. About a third of the wires had fractured and the rest had been cut. All were tensile fractures with a relatively high degree of necking. The cause of the localized heating was unknown. It can only be concluded from the investigation that the temperature did not exceed the Ac3 point of the wire material, which should be about 750 deg C, and that the heating lasted a fairly long time.
Fractured Chain Link
Authors: Naumann Friedrich Karl , Spies Ferdinand 
Published: May 2019

Abstract
A chain link which was part of the hoisting mechanism of a drop hammer broke after three or four months of service. It was reportedly manufactured of the heat resistant steel 30 Cr-Mo-V 9 (Material No. 1.7707). The fracture of the chain link had a conchoidal structure and ran along the austenitic grain boundaries. Such fractures are characteristic results of strong overheating. The coarse-grained, coarse acicular heat-treated structure of the chain link confirmed overheating. Because temperatures in excess of 1150 deg C are required for the solution of impurities, it is more probable that the real damage was done during the heat-up forging (drop-forging) and could not be removed during heat-treatment.
Broken Eyebolt
Authors: Brunsmann Gisela , Szabó Ödön 
Published: May 2019

Abstract
After several years' use, an eyebolt suffered brittle fracture in the first turn of the thread. The fracture started at the notch at the root of the thread. Neither localized material defect nor an old crack were present. The investigation showed that instead of the specified steel quality St 37-2 N, a steel with about 0.5% C had been used. The microstructure with the coarse ferrite network indicated that the forged eye bolt had been normalized either at too high a temperature or not at all. In any case the anneal at 900 deg C produced a considerably more finely grained structure. In addition, the nature of the fracture and the results of the notched bar impact tests showed that in spite of the high C-content, the eye bolt had become brittle as a result of aging.
Fractured Lock Ring of Drum
Authors: Naumann Friedrich Karl , Spies Ferdinand 
Published: May 2019

Abstract
The lock ring of a centrifuge drum was fractured after one year's operation. The ring, with a trapezoidal thread on the inside, was made of steel with approximately 0.5%C-1.3%Mn-1.1%Cr and was hardened and tempered to 105 kp/sq mm strength at 11% elongation (d10). It fractured radially in one of four places in which the cross section was weakened by short grooves that served as tool grips for tightening the cover. The fracture propagated from the base of the thread and followed it in a circumferential direction until it was broken through radially at the top across the ring due to a weakening caused by the external reduction of the cross section. The uppermost turn was corroded at the base by pitting favored by differences in ventilation and formation of Evans elements in the narrow gap between thread and counterthread. Metallographic examination showed that the pitting favored intergranular fissures and therefore it can be established that stress corrosion accelerated cracking of the ring Although since the drum was used for the processing of various liquids, the exact corroding medium cannot be stated.
Broken Inner Rings of Spherical Roller Bearings
Authors: Naumann Friedrich Karl , Spies Ferdinand 
Published: May 2019

Abstract
Inner rings of spherical roller bearings out of full hardening ball bearing steel 100 CrMn 6 (Fe-1C-1.5Cr-1.1Mn, Material No. 1.3520) failed in service. Due to the cracks, parts from the middle flange broke or the rings failed in radial direction completely. All the cracks and fracture originated from the middle flange. In all of the three rings one flank showed heavy wearing and scouring. The cracks started from the edge of this flank with the cylindrical mantle surface of the middle flange. The cracking resembled fatigue cracking. However, in a fine-grained hardened steel such as this, fracture faces due to stress-cracking and overload fracture look the same. Metallographic examination showed the failure of the rings was a result of repeated heating and rapid cooling of the surface due to the grinding of the bearings on one flank of the middle flange. The stress-cracks (grindcracks) spread in steps which finally led to the breaking off of parts from the middle flange and complete failure of the rings.
Broken Helical Compression Spring
Authors: Naumann Friedrich Karl , Spies Ferdinand 
Published: May 2019

Abstract
A helical compression spring with ten turns made of 1.8 mm thick wire which was under high pressure during tension applied to a rocker arm broke on the test stand in the third turn. The fracture was a torsion fracture that initiated in the highly loaded inner fiber and showed in its origin the characteristics of a fatigue fracture. A longitudinal fold was located at the fracture crack breakthrough which could still be observed at the fourth and fifth turns, where a further incipient crack originated. A metallographic section was made directly next to the fracture path and the fold was cut. It showed decarburized edges in the outer slanted part and this most likely occurred during rolling. The inner radially proceeding part, however, was probably a fatigue fracture originating in the fold. The fracture of this highly stressed spring was therefore accelerated by a rolling defect. In order to decrease the stress, the construction has meantime been modified.
Wear and Failure of Babbit Bushes in Steam Turbine Sliding Bearings
Authors: Barykin N.P. , Sadykov F.A. , Aslanian I.R. 
Published: May 2019

Abstract
An investigation of wear and failure of babbitt bushes was completed in this study. The results showed that wear at dry sliding of babbitt obtained by plasma spraying was less than that of babbitt in the as-cast state and after a deformation heat treatment. The failure of babbitt bushes was caused by a simultaneous and interrelated exhibition of fatigue and wear processes that depend considerably on cohesion strength between the bush and the bearing base and accumulation of defects on the contact surface between the bush and the shaft.
Coil Spring Failures in Aerospace Hardware
Authors: Frost S. W. , Kamber K. T. 
Published: May 2019

Abstract
Life testing of cyclic loaded, miniature extension springs made of 17-7 PH stainless steel wire and AISI 302 Condition B stainless steel wire has shown end hook configuration to be a major source of weakness. To avoid cracking and subsequent fatigue failure, it was found that stress concentration depended on end hook bend sharpness. Also, interference fits are to be avoided in the end hooks of small springs. Additionally, a need for careful consideration of the stress-corrosion properties of candidate materials for spring applications has been demonstrated by stress-corrosion test results for 17-7 PH CH900 and for Custom 455 CH850 stainless steels. Laboratory testing of these two materials in the form of compression springs confirmed the superiority of the 17-7 PH over Custom 455.
Failure of a Splined Shaft from a Newsprint Plant
Authors: Chan P.C. , Thornley J.C. 
Published: May 2019

Abstract
A splined shaft on a wood chip-to-fiber refiner failed during equipment start-up. The shaft broke into two pieces at a location close to the end of the splined part of the shaft. The failed component showed the classical fatigue-cracking fracture face. The shaft had a diam of approximately 140 mm (5.5 in.) in the unsplined section and was made of 4340 Ni-Cr-Mo alloy steel heat treated to a uniform hardness of HRC 31. Cracks from at least seven different origins had coalesced to produce the single large crack that resulted in failure. The origins of these cracks were on the flanks of the splines. SEM examination revealed the splined shaft failed by fretting fatigue.
Abnormal Wear of a Pinion Gear
Authors: Shah Jivan B. 
Published: May 2019

Abstract
A pinion gear made of AMS 6470 steel, nitrided all over, lost internal splined teeth due to wear. Spline failure of the power turbine gear caused an engine overspeed and disintegration. Excessive spline wear resulted from a new coupling being mated during overhaul with a worn gear spline. Wear on the spline teeth flanks of the coupling was attributed to severe wear on the mating gear (internal) spline teeth. The assigned cause was an inadequate maintenance procedure which resulted in a wear-damaged component being retained in the power train during engine overhaul. To prevent reoccurrence, specific inspection criteria were issued defining maximum limits for spline wear. A procedure and requirements were specified for installing the coupling and pinion gear at the next overhaul.
Corroded Pump Impeller
Authors: Naumann Friedrich Karl , Spies Ferdinand 
Published: May 2019

Abstract
After operating for six months, a pump impeller (of nickel-containing cast iron) showed considerable corrosion. Cross sections showed substantial penetration of the wall thickness without loss of material. The observed supercooled structure implied low strength but would not affect corrosion resistance. Etching of the core structure showed a selective form of cast iron corrosion (spongiosis or graphitic corrosion) which lowered the strength of the cast iron enough that a knife could scrape off a black powder (10.85% C, 1.8% S, 1.45% P). Analysis showed that some of the “sulfate” found in the scrubbing water was actually sulfide (including hydrogen sulfide) and was the main cause of corrosion.
Leaky Heating Coils of an Austenitic Chromium-Nickel-Molybdenum Steel
Authors: Naumann Friedrich Karl , Spies Ferdinand 
Published: May 2019

Abstract
A solution containing 50 to 70% calcium chloride (pH 7.5 to 8.5) was concentrated by evaporation in a brick-lined vessel by passing steam at a pressure of 15 atmospheres through a system of heating coils made of austenitic stainless steel X 10 Cr-Ni-Mo-Ti 18 12 (Material No. 1.4573). After five months one of the coils, which consisted of tubes having a wall thickness of 3.4 mm, developed a leak. Tightly closed cracks were seen on the outer surface of the tube. Further tests with color penetration process revealed multiple branched cracks. Longitudinal section showed that the cracks had started from the outside surface of the tube. Electrolytic etching further showed that they had propagated mainly across the grains. It was concluded that this was a typical case of transcrystalline stress corrosion.
Destroyed Screen Bars of Stainless Steel
Authors: Naumann Friedrich Karl , Spies Ferdinand 
Published: May 2019

Abstract
Screens made of stainless steel X5 Cr-Ni-Mo 18 10 (Material No. 1.4401), which were exposed to cooling water from the mouth of a river, became unserviceable after a few months because of the breaking out of parts of the bars. The multiple fracturing of the screen bars in the brackish water of the mouth of the river was attributed to stress corrosion and pitting. The steel used, which contained molybdenum, would have withstood the severe corrosive conditions in the heat-treated condition, i.e. quenched after high temperature anneal. However, the stresses caused by deformation and welding, as well as the intensification of corrosive conditions brought about by design, i.e. creation of corrosion currents in the poorly aerated gaps (Evans elements), made this impossible.
Worn Cast Iron Pump Parts
Authors: Naumann Friedrich Karl , Spies Ferdinand 
Published: May 2019

Abstract
A slide and the two guideways of a pump had to be disassembled already during run-in time after approximately 20 h because they had galled completely, before the rated speed of 800 rpm was reached. Chemical analysis of the slide showed the following composition: 3.60C, 3.22Graphite, 2.49Si, 0.51Mn, 0.485P, and 0.112S. The iron was thus distinctly hypereutectic. The galling of the pump parts therefore was favored by an unsuitable structure caused by improper composition and fast cooling. Distortion by casting stresses may have been contributory or may have played the principal part. In order to prevent a repetition, the use of hypoeutectic or eutectic iron, slower cooling of the casting, inoculation of the melt with finely powdered ferrosilicon, and possibly rounding-off the edges or machining of the surfaces are recommended.
Corroded Pipe Section of Oil Burner for Superheated Steam Generator
Authors: Naumann Friedrich Karl , Spies Ferdinand 
Published: May 2019

Abstract
A heat exchanger made of a pipe in which oil was heated from the outside from approximately 90 deg C to 170 deg C, by superheated steam of about 8 to 10 atmospheres had developed a leak at the rolled joint of the pipe and pipe bottom. The pipes were supposed to be made from St 35.29 steel and annealed at the rolled joint to 100 mm length. The outer pipe surface was strongly pitted by corrosion all around the rolled joint. In the vicinity of the steam chamber the pipe wall had oxidized through from the exterior to the interior at one spot. Adjoining this spot, grooves caused by erosion were noticeable. This was a typical case of crevice corrosion. The rolled joint evidently was not entirely tight, so that saturated steam condensate could penetrate into the gap.
Spalling Failure of a Spur Gear
Authors: Alban Lester E. 
Published: May 2019

Abstract
A portion of two large spur tooth bull gears made from 4147H Cr-Mo alloy steel that had spalling teeth was submitted for evaluation. The gears were taken from a final drive wheel reduction unit of a very large open-pit mining truck. The parts had met the material and initial heat treat hardening specifications. The mode of failure was tooth profile spalling. By definition, spalling originates at a case/core interface or at the juncture of a hardened/nonhardened area. The cause of this failure was either insufficient or no induction-hardened case along the active profile. The cause was activated by a nonfunctioning induction hardening coil that did not or was not allowed to harden the midprofile of several teeth.
Abrasive Wear Failure of a Hypoid Pinion
Authors: Alban Lester E. 
Published: May 2019

Abstract
A hypoid pinion made from 4820 Ni-Mo alloy steel was the driving member of a power unit operating a rapid transit car. The pinion had been removed from service at the end of the initial test period because it showed undue wear. The mode of failure was severe abrasive wear. The cause of failure was insufficient surface hardness, resulting from improper heat treatment. A service recall for the remaining pinions was immediately initiated.
Failure Analysis of a Radio-Activated Accelerator Component
Authors: Sommer W.F. , Maloy S.A. , James M.R. , Louthan M. , Chen J. , Ullmaier H. 
Published: May 2019

Abstract
A double-walled, hemispherical metal beam exit window made of alloy 718 developed a crack during service, leading to coolant leakage. The window had been exposed to radiation damage from 800 MeV protons and a cyclic stress from 600 MPa tensile to near zero induced by numerous temperature cycles calculated to be from 400 to 30 deg C (752 to 86 deg F). The window was activated to &gt;200 Sv/h. It was determined through analysis using remote handling techniques and hot cells that the crack initiated near a spot weld used to affix thermocouples to the window surface. In addition to analysis of the crack, some of the irradiated material from the window was used to measure mechanical properties. Hot cell techniques for preparation of samples and testing were developed to determine true operating conditions of radiation, strain, and temperature.
Corrosion of Gold Bridgewire in Electronic Components
Authors: Downs G. L. , Braun J. D. , Tibbitts E. E. 
Published: May 2019

Abstract
Accelerated aging tests on detonator assemblies, to verify the compatibility of gold bridgewire and Pd-In-Sn solder with the intended explosives, revealed an unusual form of corrosion. The tests, conducted at 74 deg C (165 deg F) and 54 deg C (130 deg F), indicated a preferential attack of the gold. To investigate the problem, a matrix of test units was produced and analyzed. Scanning electron microscopy, EDX analysis, and x-ray diffraction techniques were used to determine the extent of the corrosion and identify the corrosion products. The results indicated that the preferential attack of the gold was due to HCN formed by decomposition of the explosive powder at high temperatures. Other associated reactions were also observed including the subsequent attack of the solder by the gold corrosion product and degradation of the plastic header.
Failure Analysis of Launch Pad Tubing From the Kennedy Space Center
Authors: McDanels S.J. 
Published: May 2019

Abstract
Piping and structural components used in space launch facilities such as NASA's Kennedy Space Center and the Air Force's Cape Canaveral Air Station face extreme operating conditions. Launch effluent and residue from solid rocket boosters react with moisture to form hydrochloric acid that settles on exposed surfaces as they are being subjected to severe mechanical loads imparted during lift-off. Failure analyses were performed on 304 stainless steel tubing that ruptured under such conditions, while carrying various gases, including nitrogen, oxygen, and breathing air. Hydrostatic testing indicated a burst strength of 13,500 psi for the intact sections of tubing. Scanning electron microscopy and metallographic examination revealed that the tubing failed due to corrosion pitting exacerbated by stress-corrosion cracking (SCC). The pitting originated on the outer surface of the tube and ranged from superficial to severe, with some pits extending through 75% of the tube's wall thickness. The SCC emanated from the pits and further reduced the service strength of the component until it could no longer sustain the operating pressure and final catastrophic fracture occurred. Corrosion-resistant coatings added after the investigation have proven effective in preventing subsequent such failures.
Corrosion of Steel Pipe in a Heating and Cooling System
Authors: Khan A.H. 
Published: May 2019

Abstract
A shopping mall in South Carolina was originally constructed in 1988 and a second phase completed in 1989. The HVAC system inside the mall included an open, recirculating condenser water loop that served various fan coil units located within tenant spaces. The system had a recirculating capacity of about 44,000 gal (166,000 L) of water. It consisted primarily of steel pipes fitted with threaded connectors on the 2 in. (46 cm) pipes and bolted flanged couplings on the larger pipes. Seven years following the completion of the mall, corrosion problems were noted at the outer and inner surfaces of the pipe. Visual observations on the inner diametral surfaces revealed that the pipes were, in almost all cases, filled with corrosion products. A significant amount of base metal loss was documented in all of the samples. The cause of the observed corrosion was determined to be a lack of corrosion monitoring and poor water quality. Pipe replacement and a regular water testing program were recommended.
Failure Analysis of a Reduction Furnace Heat Resistant Roll
Authors: Milner R.D. 
Published: May 2019

Abstract
A failure analysis was conducted in late 1996 on two rolls that had been used in the production of iron and steel powder. The rolls had elongated over their length such that the roll trunnions had impacted with the furnace wall refractory. The result was distortion and bowing of the roll bodies which necessitated their removal from service. The initial analysis found large quantities of nitrogen had been absorbed by the roll shell. Further research indicated nitrogen pickup accounted for 3% volumetric growth for every 1% by weight nitrogen absorption. This expansion was sufficient to account for the dimensional change observed in the failed rolls. This paper details the failure analysis and resulting research it inspired. It also provides recommendations for cast material choice in highly nitriding atmospheres.
Creep Rupture of a Carbon Steel Furnace Tube
Authors: Ogden Paul 
Published: May 2019

Abstract
A carbon steel furnace tube which should have given good service for ten years ruptured after one year. The tube showed obvious swelling at the point of rupture, and the bulged surface of the tube was oxidized at a temperature far above the design temperature. There was little or no loss in wall thickness due to corrosion or scaling, and the tube wall was thinned to a knife edge at the rupture. Metallographic examination showed the condition of the material was satisfactory. The failure was mechanical in nature, typical of short time creep rupture. The localized oxidation indicated improper furnace operation or blockage of the tube. The furnace was checked and found to have a burner tip out of order. After the tip was repaired, localized overheating was minimized and further premature failures did not occur.
Fractures of Electro-Galvanized Cylinderhead Screws
Authors: Naumann Friedrich Karl , Spies Ferdinand 
Published: May 2019

Abstract
Eight cylinderhead screws cracked after a short running time in motors. They were made of Fe-0.45C-1Cr steel, had rolled threads, were heat treated to 110 kg/sq mm tensile strength, and were electrolytically galvanized. All fractured at the root of the thread. The surfaces of fracture were fine-grained and had not spread by rubbing. Because the screws were electrolytically galvanized, failure resulted from “delayed fracture.” Experience has shown that this type of fracture is seen on production parts made of high-strength steels, which absorbed hydrogen during pickling or during a galvanic surface treatment. Such parts will rupture below the elastic limit during continuous stressing. This often occurs only after the expiration of a certain time period, and preferably at locations of stress concentrations such as changes in cross section or threads. As a rule, the hydrogen cannot be verified analytically because most of it escapes again after prolonged storage at room temperature or short heating at 100 to 200 deg C.
Broken Slide of a Friction Press
Authors: Naumann Friedrich Karl , Spies Ferdinand 
Published: May 2019

Abstract
A short fracture section of a forged and normalized Ck 35 (DIN 17200) steel slide showed three distinct zones: a dark colored crystalline area, an incipient crack propagating into a far advanced, rubbed fracture surface, and a fine crystalline final break. Metallographic examination showed the dark incipient crack was present before the last heat treatment and was oxidized and decarburized prior to the conclusion of the annealing process. The crack ran perpendicular to the fiber, so it was not formed before or during forging. It was a thermal stress crack produced during flame cutting of the middle section of the slide. The initial crack acted as a sharp notch favoring the formation of the fatigue fracture which lead to the failure of the slide.