The development of design guidance for stainless steel structures requires more tests on ferritic grade connections. This paper deals with a series of lap shear tests which have been carried out on ...various configurations of bolted and screwed connections. The tests demonstrate net section failure, bearing failure and block tearing failure. The material is a ferritic stainless steel of grade 1.4509 (AISI 441) with a thickness of 0.5–4.5mm. The results are utilized in developing design guidance in accordance with Eurocodes.
•A series of lap shear tests of bolted and screwed ferritic stainless steel connections was carried out.•EN 1993-1-1 approach is recommended for net section resistance and in EN 1993-1-8 approach for bearing and block tearing resistances.•If the failure criterion is the ultimate load in test, the design expression given in EN1993-1-1, EN 1993-1-3 and EN 1993-1-8 result in all tests in a safe outcome.•In order to ensure that the deformation at the fasteners is not too large in SLS, an extra reduction factor of 0.9 should be considered in some cases.
•Paper presents a comparison of two low carbon steels during deep drawing process.•The cracks occurred in longitudinal direction of rolled steel.•This study highlights the detrimental effect of the ...interface cementite grain/ferrite matrix under deep drawing conditions.•Carbon content below 0.02wt.% prevents the formation of cementite which improves the deep drawing capability of steel.
This paper presents a comparison in behaviour of two Zn coated, low carbon steels during deep drawing of bearing housing. The failures occurred during deep drawing process only for one steel. The experimental work consisted of a visual inspection, microscopic examination and chemical analysis of both materials. Metallurgical tests revealed the difference in microstructure and in carbon content. The anisotropy in behaviour was observed during deep drawing process. Metallography confirmed formation of longitudinal micro and macrocracks and elongated chains of cementite particles in matrix of ferrite. This study highlights the detrimental effect of the interface cementite particle/ferrite matrix as the main reason for the microcracks formation and reduction of steel capacity for deep drawing.
During a test in a wet salt (NaCl) chamber rusty spots and elongated pits appeared on the brushed surface of a prototype casing for a household device made from AISI 304 stainless steel. The ...corrosion pits only formed on the brushed surface and on the deformed edges. Metallography revealed deformation-induced martensite and delta ferrite in the microstructure. In the wet salt environment the brushed surface showed a lower corrosion resistance than the non-brushed surface. The corrosion was explained as being due to damage to the protective oxide layer with brushing, insufficient re-passivation and the presence of iron particles. The corrosion propensity of the brushed surface of the casing was increased by the presence of deformation-induced martensite, delta ferrite and, probably, the remains of iron particles. The use of AISI 316 stainless steel, alloyed with molybdenum, would be more appropriate for avoiding the formation of corrosion pits due to chloride ions in a wet environment.
Inclusions in primary aluminium were analysed with an electron-probe microanalyser and a high-resolution Auger electron spectrometer. In multiphase eutectic and complex inclusions the presence of ...calcium, magnesium, iron, copper, molybdenum and aluminium was detected. Prior to Auger analysis, sufficient ion etching is necessary for the elimination of oxides from the surface. The complex inclusions, with calcium content, reacted with water which demanded the choice of a suitable technique for the preparation of metallographic samples.
The complex nitrides of intermetallics based on titanium, aluminium and nickel are very promising materials for high-performance coatings. Samples of Ni
3Al and TiAl
3 were prepared by the ...self-propagating high-temperature synthesis (SHS) of elemental powders in an argon atmosphere with subsequent pulsed-plasma ion nitriding. Results from the combustion synthesis of aluminides of nickel and titanium followed by ion nitriding are presented. X-ray photoelectron spectroscopy (XPS) analysis of the Ni
3Al confirmed the formation of a nitride with a binding energy Al 2p 74.6
eV, the formation of AlN was observed for both aluminides; however, the presence of TiN nitride was not confirmed for the TiAl
3.
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