摘要:

AbstractLimitations of surface treatments can be apparent under the complex loading experienced by engineering parts and components. These limitations can be removed by using duplex techniques. The process combination of thermal spraying and nitriding makes it possible to produce coatings with increased resistance for applications involving complex stress and loading conditions. The interactions between thermal spraying and nitriding have been investigated and both processes optimised to achieve improved properties of the compound coatings. Metallographic, X-ray, wear, and corrosion test results for the compound coatings are presented.

ISSN:0267-0844    

DOI:10.1179/sur.1996.12.4.229

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

ISSN:0267-0844    

DOI:10.1179/sur.1996.12.4.265

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

ISSN:0267-0844    

DOI:10.1179/sur.1996.12.4.267

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

ISSN:0267-0844    

DOI:10.1179/sur.1996.12.4.270

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

ISSN:0267-0844    

DOI:10.1179/sur.1996.12.4.296

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

ISSN:0267-0844    

DOI:10.1179/sur.1996.12.4.298

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

AbstractLimitations of surface treatments can be apparent under the complex loading experienced by engineering parts and components. These limitations can be removed by using duplex techniques. The process combination of thermal spraying and nitriding makes it possible to produce coatings with increased resistance for applications involving complex stress and loading conditions. The interactions between thermal spraying and nitriding have been investigated and both processes optimised to achieve improved properties of the compound coatings. Metallographic, X-ray, wear, and corrosion test results for the compound coatings are presented.

ISSN:0267-0844    

DOI:10.1179/sur.1996.12.4.299

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

AbstractMany of the state of the art thermal spray coatings (e.g. plasma, HVOF) have been developed with wear resistance as a primary aim. However, these coatings are increasingly being required to function in aqueous environments and, to date, their corrosion behaviour is not well defined. This paper comprises a description of a study of the corrosion behaviour of two types of thermal sprayed cermet coatings applied to a superduplex stainless steel (UNS S32760) substrate. Both coatings (86WC-10Co-4Cr and 50WC-50Ni-Cr-B-Si) were applied using a proprietary HVO F process. Each generic coating was studied in three forms: unsealed, sealed using a polymeric sealant, and with an interlayer of Inconel 625 applied between coating and substrate. Surfaces were tested in both the as sprayed condition and after abrasion and polishing to 1üm. The coatings were exposed to seawater and a low total dissolved solids (TDS) water at 18 and 50°C. The corrosion behaviour and detailed corrosion mechanisms were investigated using electrochemical monitoring techniques supported by precise post-test microscopical examination using light microscopy, scanning electron microscopy, and X-ray microanalysis. The two coatings studied are shown to be susceptible to corrosion after relatively short periods in both the low TDS water and seawater. Distinct differences in the extent and mechanisms of attack are demonstrated. In addition, the findings from electrochemical accelerated tests are shown to correlate well with the results of detailed examination of specimens after longer term exposure to the aqueous environments.

ISSN:0267-0844    

DOI:10.1179/sur.1996.12.4.303

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

AbstractNumerical models of austenite formation during rapid heating of steels are presented. Shifted transformation temperatures, diffusion controlled growth, impingement effects, and the possibility of diffusion less growth are considered. Local equilibrium at the phase interfaces is assumed. Further, the effect of alloying elements under paraequilibrium conditions is taken into account. The model is applied to electron beam hardening of hypoeutectoid steels in order to predict the properties of the hardened zone.

ISSN:0267-0844    

DOI:10.1179/sur.1996.12.4.313

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

AbstractIn the present work the influence of solidification conditions on the primary solidification modes of two martensitic stainless tool steels (AISI 420 and AISI 440C) is analysed, with the aim of establishing a basis for the selection of the laser treatment parameters that lead to the most favourable microstructures. Kurz, Giovanola, and Trivedi s solidification model is used to analyse the competition betweenδferrite and austenite during solidification. The theoretical calculations are compared with experimental results obtained after laser surface melting of AISI420 and AISI 440C with scanning speeds from 1×10−3to 2×10−1m s−l. Calculated results are in good agreement with experimental observations and it is shown that, although the equilibrium solidification mode of both steels used isδferrite, the precipitation of primary austenite from the liquid is kinetically favoured.

ISSN:0267-0844    

DOI:10.1179/sur.1996.12.4.319

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor