XPS, XRD and laser raman analysis of surface modified of 6150 steel substrates for the deposition of thick and adherent diamond-like carbon coatings

Abstract

Although the 6150 steel has an excellent fatigue and impact resistance, it is unsuitable to operate it when the corrosion is a limited factor. We propose here a sequence of steel pre-treatment by carburizing, carbonitriding and nitriding in order to improve the poor adhesion between Diamond Like-Carbon coatings on steel. This sequence is our attempt to reduce the difference between the coefficients of thermal expansion of steel and DLC through the graded interface. This work demonstrates the quantitative analysis of the molecules present at surface using X-ray photoelectron spectroscopy. The crystallographic structures are investigated by X-ray diffraction which shows the formation of carbides and nitride phases. Raman spectroscopy reveals the carburizing surface characteristics where DLC coating is nucleated and grown at the substrate. At the end of the analysis it is possible to verify which molecules and phases are formed on the steel surface interface after each step of pre-treatment.

Methods of data analysis for the ball cratering test on TiN and DLC coated steel

“…In As expected, the roughness of the TiN deposited by PVD system was low and follows the shape of the substrate, indicating that the coating has satisfactory adhesion. In the other hand, DLC is a new technology and needs better attention due adhesion issues that limits its use 15,16 , although is an interesting type of coating because of its high hardness and chemical inertness 17 . The DLC with 1 μm thickness shows satisfactory adhesion, and the interface between coating and substrate is clear, as shown in Figure 4.…”

Structural analysis of a-C:H and a-C:H:Si films under high-pressure and high-temperature by synchrotron X-ray diffraction

“…provides an accurate existence percentage for hydrogen atoms in films, and the hydrogen atom contents for various films have been quantified 45) . X-ray diffraction (XRD) is not so major for such film analysis, but the residual stress in films has been quantified in the past studies 1,[46][47][48] . XRD is excellent for quantitative analysis of bonding structures because it enables the number of sp 2 and sp 3 bonds to be individually estimated in principle if the pair distribution functions can be obtained because the atomic distances in sp 2 and sp 3 bonding structures differ.…”

The Effect of Immersion Time and Immersion Temperature on the Corrosion Behavior of Zinc Phosphate Conversion Coatings on Carbon Steel

“…Despite its relatively limited corrosion resistance, carbon steel is used in large tonnages in marine applications, chemical processing, petroleum production and refining, construction and metal processing equipment 1,2 . The economic consequences of corrosion of iron and its alloys in various industrial sectors, including oil and gas operations, are investigated 3 . There are different ways to control corrosion including inhibitors, coatings, applying anodic/cathodic protection and proper design 4 .…”