Tribological Behavior of New Martensitic Stainless Steels Using Scratch and Dry Wear Test

Abstract

This paper focuses on the tribological characterization of new martensitic stainless steels by two different tribological methods (scratch and dry wear tests) and their comparison to the austenitic standard stainless steel AISI 316L. The scratch test allows obtaining critical loads, scratch friction coefficients, scratch hardness and specific scratch wear rate, and the dry wear test to quantify wear volumes. The damage has been studied by ex situ scanning electron microscopy. Wear resistance was related to the hardness and the microstructure of the studied materials, where martensitic stainless steels exhibit higher scratch wear resistance than the austenitic one, but higher hardness of the martensitic alloys did not give better scratch resistance when comparing with themselves. It has been proved it is possible to evaluate the scratch wear resistance of bulk stainless steels using scratch test. The austenitic material presented lower wear volume than the martensitic ones after the dry wear test due to phase transformation and the hardening during sliding.

Corrosion and nanomechanical behavior of high strength low alloy steels

“…The Lc2 values for the steels are in line with the nanomechanical properties as shown in Figure . Close observation of the scratch track in Figure a,b reveals materials removal and micro‐cracks extending laterally from the edges of the scratch, indicating chipping occurred during the scratch test for the alloys as reported by many authors on similar behavior of the scratch track for other martensitic stainless steels …”

“…Close observation of the scratch track in Figure 4a,b reveals materials removal and micro-cracks extending laterally from the edges of the scratch, indicating chipping occurred during the scratch test for the alloys as reported by many authors on similar behavior of the scratch track for other martensitic stainless steels. [19,20] The scratch friction coefficient (SFC) was also calculated by dividing the tangential force (F t ) by the applied normal force (F n ), which allowed to compare the scratch resistance of the steels. Figure 5 shows the variation of SFC as a function of the applied normal force for the steels.…”

Tribocorrosion behavior of new martensitic stainless steels in sodium chloride solution

“…This is not surprising since the shakedown maps were obtained for entirely mechanic behavior and it does not take into account the involved mechanisms taking place in a tribocorrosion system. Therefore, only in the dry wear tests previously performed [16] under the same tribological conditions (load, sliding speed and duration) big differences between the austenitic and martensitic stainless steels wear behavior were observed (the martensitic materials showed more than four times higher wear volumes than the austenitic one). These differences between the wear behavior of the same tested materials in dry and wet conditions have been also observed by Espallargas and Mischler [40].…”

“…The chemical compositions of the alloys are presented in Table 1. Their corresponding heat treatments and microstructures are presented elsewhere [16].…”

“…Indeed, cracks were found in some cases in the subsurface worn area of the studied materials, Figure 9. It is known that the studied stainless steels, with lath martensite microstructure and low carbon content [16], present low stacking fault energy which can be related to the trend of developing more dislocations during plastic deformation [35] [36], thus favoring strain accumulation and probability of crack formation and propagation. However, no systematic crack evolution was found and further research is needed to understand the crack initiation.…”