Browsing by Author "Crimello, Pablo"

Filter results by typing the first few letters
Now showing 1 - 3 of 3
  • Thumbnail Image
    Item
    Development of a post oxidizing process over nitrided and nitrocarburized steels for wear and corrosion protection
    (2018-09-20) Brühl, Sonia Patricia; Dalibón Bähler, Eugenia Laura; Cabo, Amado; Carfi, Guillermo Rodolfo; Crimello, Pablo
    The environmental concern on the use of this coating stimulated the research activities for alternatives of hard chromium. In this work, AISI 1045 was nitrocarburized, AISI 4140 was nitrided, both in a DC Plasma industrial equipment, and they were oxidized as prost treatment in the same chamber.
  • Thumbnail Image
    Item
    Extensión de durabilidad de pistones de bombas de fractura hidráulica mediante el empleo de tecnología de nitruración por plasma y PVD
    (2017-05-10) Crimello, Pablo; Brühl, Sonia Patricia; Aguirre, Luis Alberto; Morris, William; Carfi, Guillermo Rodolfo
    En la industria del Gas y del Petróleo (Oil&Gas), el concepto de fractura hidráulica consiste en romper la formación (reservorios) por intermedio de un fluído, básicamente formado por agua y arena que bombeado a una determinada presión y un caudal, supere la resistencia de la formación, de manera de colocar dentro de las fisuras creadas un ordenamiento del agente de sostén, impidierndo el cierre de las mismas. Siguiendo criterios ampliamente difundidos en la ingeniería de superficie, se propuso por tanto reemplazar esta técnica de endurecimiento superficial por la Nitruración por plasma, la cual genera una transición gradual de durezas desde el núcleo hacia la superficie, eliminando la presencia de interfaces.
  • Thumbnail Image
    Item
    Wear and adhesion properties of a PVD duplex coated medium alloy steel for plungers in the oil and gas industry
    (2017-07-05) Brühl, Sonia Patricia; Dalibón Bähler, Eugenia Laura; Cabo, Amado; Crimello, Pablo; Aguirre, Luis Alberto; Carfi, Guillermo Rodolfo
    A duplex coating consisting in plasma nitriding of V820 steel (Boehler®) and a CrAlN coating (Balinit©, Oerlikon Balzers) was designed to enhance wear properties of hydraulic fracture pumps plungers used in the O&G Industry. On subsequent reciprocating motions, pumped slurry (containing solid particles) would eventually penetrate the interstice between the plunger´s operating surface and the seal, thus causing permanent damage. The duplex system was analyzed comparing to a standard treatment for these pistons (thermal sprayed coating over carbon steel): optical and electronic microscope, depth hardness profiles, EDS and DRX. Two groups of coated samples were selected with different surface finishing, and the nitrided sample was used for comparison, so as the untreated steel. Scratch Test at different constant loads and Rockwell C indentation were used to test adhesion. Abrasion wear tests were carried out following ASTM G65. Finally, laboratory results were compared to field tests. The PVD coating were 2500 HV hard, 3-4 microns thick, and the nitrided layer provided a soft hardness depth profile of about 320 microns width. The standard thermal spray coating was 800 microns thick, with an average hardness of 750 HV but with an abrupt change in hardness with the substrate. The adhesion was extremely good, critical load was 125 N. In the abrasive tests, the mass loss in the PVD coated samples was reduced 30 times respect to the standard coated samples. In the field technological test the PVD coated pistons improved the quantity of pumping cycles in almost 300%.