The impurities sulphur, phosphorus, lead, bismuth, tin and antimony affect the hot workability of stainless steels. In this study, the authors show that sulphur and lead segregate to phase and ...solidification grain boundaries, where cracks appear during hot deformation. The workability was tested by the hot rolling and hot bending of industrial and laboratory steels.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
The impurities sulphur, phosphorus, lead, bismuth, tin and antimony affect the hot workability of stainless steels. In this study we show that lead segregate to phase and solidification-grain ...boundaries, where cracks appear during hot deformation. The workability was tested by the hot bending of laboratory steels.
Failure of crane wire rope Torkar, M.; Arzenšek, B.
Engineering failure analysis,
04/2002, Letnik:
9, Številka:
2
Journal Article
Recenzirano
A failure analysis of a broken multi strand wire rope from a crane was performed. The fracture of the steel wires in the wire rope showed characteristics of fatigue. On the wire surface were observed ...decarburised cracks which act as initiation sites for fatigue crack propagation during the application of the wire rope. The main reasons for the failure of the wire rope were fatigue and poor inspection.
The fracturing of structural steels in Charpy ductile range is investigated. The dependences load versus deflection and time were recorded and the consumption of energy for different fracturing ...events, as f.i. plastic deflection and crack propagation was assessed. The micromorphology of the crack surface and lips is examined and the succesions of decohesion mechanims is deduced. The aproximate change of fracturing temperature due to adiabatic dissipation of deformation energy as heat is deduced, also.
On different austenitic stainless steels tensile tests were carried out in the hot working temperature range for 800 to 1200ºC. The effects of δ ferrite on recrystallisation, of σ phase on ...deformability and the effect of temperature on recovery, recrystallisation and grain growth were established.
The failure of a secondary steam circuit valve was investigated. Several fatigue cracks were initiated on valve shafts in the angle of the groove supporting the puppet. Cracks propagated obliquely ...toward the shaft end. The final shaft fracture occurred by shearing in valve position closed, when the shaft bearing section was diminished sufficiently. The surface of the split ring transmitting the puppet weight to the shaft was worn irregularly. Fatigue cracks initiated and propagated in the split ring groove angle due to resonance stresses at the start of the operation, when the temperature of the valve was low and the shaft steel notch toughness was also low.
A transition layer of width 5 - 10 μm was found on the boundary between ductile and brittle fracture for Charpy V notch specimens in the transition temperature range of a structural steel having a ...microstructure of polygonal ferrite -pearlite. The fracture mode in the transition layer was shearing with occasional submicrometre dimples. From tensile tests on notched specimens, the cleavage fracture stress and flow stress by ductile decohesion were determined. Based on the experimental data and the assumption that the volume of metal involved in the plastic deformation during fracture was related to the volume of the dimples, it was deduced that the transition layer width represents the size of the plastic zone immediately before cleavage initiation. The crack opening displacement and the crack tip radius for the change of fracture mode were calculated.
The impurities sulphur, phosphorus, lead, bismuth, tin and antimony affect the hot workability of stainless steels. In this study, the authors show that sulphur and lead segregate to phase and ...solidification grain boundaries, where cracks appear during hot deformation. The workability was tested by the hot rolling and hot bending of industrial and laboratory steels. PUBLICATION ABSTRACT
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
On different austenitic stainless steels tensile tests were carried out in the hot working temperature range for 800 to 1200 deg C. The effects of delta ferrite on recrystallisation, of sigma phase ...on deformability and the effect of temperature on recovery, recrystallisation and grain growth were established.
