Investigation on the parameters optimization and sliding wear behaviors under starved lubrication of discrete laser surface hardened 25CrNi2MoV steel

2021 ◽  
pp. 107176
Author(s):  
Xiongfeng Hu ◽  
Siyu Jia ◽  
Fuqiang Lai ◽  
Li Jiang ◽  
Xiaoqiang Li ◽  
...  
2005 ◽  
Vol 167 (1) ◽  
pp. 83-90 ◽  
Author(s):  
Rakesh Kaul ◽  
P. Ganesh ◽  
Pragya Tiwari ◽  
R.V. Nandedkar ◽  
A.K. Nath

1986 ◽  
Vol 108 (3) ◽  
pp. 326-333 ◽  
Author(s):  
P. A. Molian ◽  
Mark Baldwin

The influence of laser surface transformation hardening on the sliding wear characteristics and mechanisms of ASTM class-40 gray and 80-55-06 ductile cast irons was investigated. A 1.2 kw, continuous wave, CO2 gas laser was employed to scan the beam successively across the surfaces of cast irons to generate hardened and tempered layers with various case depths. A pin-on-disk wear test system was then used to study the wear behavior as functions of case depth, microstructure, hardness, and surface roughness. As expected, a dramatic improvement in resistance to scuffing and sliding wear was obtained. However, the most significant result was the occurrence of negligible oxidational wear for a load range that increased with an increase in case depth. Resistance to mild and severe wear, mild-to-severe wear transition load, and frictional heating were increased with an increase in case depth. Analysis of worn surfaces and wear debris revealed that negligible oxidational wear in laser-hardened irons is due to two mechanisms: oxidation and adhesion of oxide to the substrate. In contrast, the mild oxidational wear of untreated irons occurs through the formation of loose oxide debris. The mechanisms of severe wear were plastic deformation, delamination, and adhesion; the rate process was controlled by adhesion for laser hardened irons and delamination for untreated irons.


2015 ◽  
Vol 92 ◽  
pp. 136-145 ◽  
Author(s):  
Qichun Sun ◽  
Tianchang Hu ◽  
Hengzhong Fan ◽  
Yongsheng Zhang ◽  
Litian Hu

2003 ◽  
Author(s):  
W. Pang ◽  
H. C. Man ◽  
T. M. Yue

Laser surface coating of Mo, WC and Mo-WC powders on the surface of Ti6Al4V alloys using a 2kW Nd-YAG laser was performed. The dilution effect, microstructure, microhardness and wear resistance of the fabricated MMC coating were investigated. With a constant thickness of pre-placed powder, the dilution levels of the alloyed layers were found to be increased with the incident laser power. The fabricated MMC layer was metallurgically bonded to the Ti6Al4V substrate. The microhardness of the fabricated surface layer was found to be inversely proportional to the dilution level. The EDAX and XRD spectra results show that new intermetallic compounds and alloy phases were formed in the laser fabricated layer. With increasing weight percentage content of WC particles in the Mo-WC pre-pasted powder, the microhardness and sliding wear resistance of the laser surface coating were increased by 87% and 150 times respectively as compared with the Ti6Al4V alloy.


2009 ◽  
Vol 628-629 ◽  
pp. 697-702 ◽  
Author(s):  
Sheng Lei ◽  
Quan Kun Liu ◽  
Yu Ping Liu ◽  
Heng Li

Microstructure, microhardness and tribological properties of laser hardened GCr15 steel were investigated in this paper. The wear resistance under lubricated sliding conditions was compared between specimens treated with laser and those of conventionally hardened. The tribological properties of laser surface-quenched GCr15 steel specimens were slightly better due to the effects of the microstructure hardening, high hardness and toughness, with the wear rate (in the order of 10-6mg/Nm) lower than that of the conventionally treated specimens. At the steady state, the frictional coefficient of laser-treated samples had no obvious difference from that of the conventionally treated samples. The wear mechanism for both cases was similar, generally involved surface fatigue wear and slight abrasion wear. LeiQ.K. Liu S. Lei Introduction H. Li In recent years, among the various surface modification methods, laser-induced surface modification has gained much attention for achieving the desired properties for applications[1]. This method is mainly used for ferrous alloys which undergo martensitic transformation and thus form a very hard surface layer with negligible surface roughness and distortion[2]. Some ideas demonstrated that the wear rate at a particular contact pressure can be strongly influenced by the microstructure of the steel, but there is also contrary idea that under the conditions of mild wear, the microstructural constituents of steels have no significant influence on the wear rate, although they affect the rate of severe wear. Previous studies of the authors demonstrated that under the dry sliding wear conditions, laser surface-hardened specimens of ferrous alloys exhibited enhanced wear resistance than conventionally hardened specimens. The aim of the study is to investigate the lubricated sliding wear behaviors of laser surface hardened GCr15 steel specimens and to compare the effect of the different microstructure compositions for laser transformation hardening with those of conventionally hardened and quenched. Moreover, the wear properties of the GCr15 steel and its corresponding wear mechanism under the lubricated wear conditions will also be studied.


Wear ◽  
1991 ◽  
Vol 142 (2) ◽  
pp. 383-386 ◽  
Author(s):  
W.J. Tomlinson ◽  
M. Cash ◽  
A.S. Bransden

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