Martensitic Stainless Steel Coatings Research Articles

Erosion Wear Behavior of HVAF-Sprayed WC/Cr3C2-Based Cermet and Martensitic Stainless Steel Coatings on AlSi7Mg0.3 Alloy: A Comparative Study

The paper presents a comparative study of the erosion wear resistance of WC-10Co4Cr, Cr3C2-25NiCr and martensitic stainless steel (SS) coatings deposited onto an AlSi7Mg0.3 (Al) alloy substrate by high-velocity air‒fuel (HVAF) spraying. The influence of the abrasive type (quartz sand or granite gravel), erodent attack angle, thickness, and microhardness of the coatings on their and Al substrate’s wear resistance was comprehensively investigated under dry erosion conditions typical for fan blades. The HVAF-spraying process did not affect the Al substrate’s structure, except for when the near-surface layer was 20‒40 μm thick. This was attributed to the formation of a modified Al-Si eutectic with enhanced microhardness and strength in the near-substrate area. Mechanical characterization revealed significantly higher microhardness values for the cermet WC-10Co4Cr (~12 GPa) and Cr3C2-25NiCr (~9 GPa) coatings, while for the SS coating, the value was ~5.7 GPa. Erosion wear tests established that while Cr3C2-25NiCr and SS coatings were more sensitive to abrasive type, the WC-10Co4Cr coating exhibited significantly higher wear resistance, outperforming the alternatives by 2‒17 times under high abrasive intensity. These findings highlight the potential of HVAF-sprayed WC-10Co4Cr coatings for extending the service life of AlSi7Mg0.3-based fan blades exposed to erosion wear at normal temperatures.

Microstructural characterization of AISI 431 martensitic stainless steel coatings deposited by laser metal deposition

Microstructural characterization of AISI 431 martensitic stainless steel coatings deposited by laser metal deposition

Comparative analysis of microstructure and corrosion resistance in laser-clad austenitic and martensitic stainless-steel coatings

Post-casting austenite often possesses better corrosion resistance than martensite. In order to compare the difference of corrosion resistance between austenitic stainless steel coating (ASSC) and martensitic stainless steel coating (MSSC) in the powder metallurgical state, two stainless steel Fe-based alloy coatings of the same process parameter were prepared on the surface of 40Cr steel by using laser cladding technology. Through SEM, EBSD, XRD and electrochemical tests, the microstructure, phase and cross-section metallurgical bonding condition of the coating were studied, and the difference in corrosion resistance between the two was comprehensively analyzed. The results showed that the main phase structure of ASSC was the FCC phase, and the main phase structure of MSSC was the BCC phase. The average self-corrosion current (9.92 × 10−8 A/cm2) and average self-corrosion rate (1.04 × 10−3 g/m2·h) of MSSC were 4.77 % and 5.62 % of ASSC, respectively. In addition, the polarization resistance, impedance value, and passivation film density of MSSC are higher than ASSC, MSSC has less damage from corrosion. The combination of factors, such as fabric refinement and passivation film density, makes the corrosion resistance of MSSC better than ASSC.

Improvement in Fretting Wear Properties of AISI 4135 Steel by Laser-Cladded Martensitic Stainless Steel Coatings

Improvement in Fretting Wear Properties of AISI 4135 Steel by Laser-Cladded Martensitic Stainless Steel Coatings

Underlying Mechanism for “Loss of Passivation” Effect of a High-Carbon Martensitic Stainless Steel Coating via Laser Cladding

Recently, laser cladding (LC) technology has become a cost-effective and convenient method to protect metal substrate from corrosion by producing metal coating with high corrosion resistance. In order to fully investigate the pitting mechanism for high carbon martensitic stainless steel (HMSS) coating, the microstructure and pitting performance of high-carbon martensitic stainless steel (HMSS) samples, which were produced via laser cladding (LC) and hot isostatic pressing (HIP) were comparatively investigated via electrochemical measurements and electron microscopies. Dendritic and network connected M23C6 carbides are the main precipitates in the HMSS coating, while the M23C6 carbides in HMSS bulk are spherical or elongated in shape. Pitting resistance of the HMSS coating is dramatically deteriorated. The massive and continuously distributed dendritic M23C6 carbides could form a large-area cathode and cause the micro-galvanic corrosion of the HMSS-LC coating matrix, thus can be considered as underlying factor for the “loss of passivation (LOP)” effect of the HMSS coating.

Microstructure and Properties of Laser Cladding Martensitic Stainless Steel Coating on Large Wind-Power Bearing Raceway Surface

Microstructure and Properties of Laser Cladding Martensitic Stainless Steel Coating on Large Wind-Power Bearing Raceway Surface

Design and development of TiC-reinforced 410 martensitic stainless steel coatings fabricated by laser cladding

AISI 410 martensitic stainless steel (MSS) coatings, reinforced with TiC ceramic particles of varying contents (0, 5%, 10% and 15%), have been fabricated by laser cladding technology for the first time in this study. The microstructure evolution and properties of the laser-cladded specimens are carefully investigated by advanced techniques, including XRD, SEM, TEM, EDS, a micro-hardness tester and a ball-on-disc tribological tester. The obtained results show that the as-cladded 410 MSS coating is mainly composed of coarse lath martensite (M), a few austenite (A) and M23C6. After addition of TiC ceramic particles, the lath-shaped M is significantly refined, meanwhile the nano-sized Ti-enriched ceramic precipitates (TiC and Ti(C,N)) are formed in the composite coatings. However, microcracks and pores occur in the laser-cladded coating with addition of TiC up to 15%. It is found that both the microhardness and wear resistance of the coatings are enhanced with an increasing TiC content, and the 10% TiC-reinforced coating exhibits the optimal comprehensive performance, with much higher microhardness and wear resistance in comparison to the TiC-free MSS coating. The remarkable properties of the TiC-reinforced 410 MSS coatings can be mainly ascribed to the synergistic effects of microstructural refinement, nano-precipitation hardening and second-phase strengthening.

Robust regression analysis for the relationship between welding parameters and microhardness of 410 NiMo martensitic steel deposits on SAE 1020 steel

The objective of this study was to analyze the flux-cored arc welding (FCAW) welding parameters and microhardness levels on surface quality of 410 NiMo martensitic stainless-steel coatings. The parameters of the FCAW process applied to the coating, included pulsation frequency, voltage, welding speed, average current and contact tip to work distance. The welding was carried out by the pulsed tubular wire process with pulsed current, constant voltage, Ar+2% O2 shielding gas and short-circuit metal transfer for the deposition of EC410 NiMo Martensitic Steel Deposits alloy coatings on a SAE 1020 steel substrate. For the statistical analysis, the Taguchi experimental planning was applied to test the influence of the parameters of the FCAW process (average current, CTWD, pulsation current and welding speed) on the coating properties. The best configuration with respect to the increased microhardness of the fusion zone in the coating welding process is: Average Current 200 A; CTWD 40 mm; Pulsation Frequency 26.31 Hz and Welding Speed 300 mm min.-1. The lowest microhardness of the melting zone in the coating welding process is: Average Current 170 A; CTWD 30 mm; Pulsation Frequency 23.26 Hz and Welding Speed 400 mm min.-1.

Development of high strength and ductile martensitic stainless steel coatings with Nb addition fabricated by laser cladding

Abstract In the present work, martensitic stainless steel (MSS) coatings with niobium (Nb) contents of 0–1.0 wt%, combining high strength and ductility with improved corrosion resistance, have been developed and fabricated by a laser cladding technique. The effects of Nb-microalloying on the microstructure and properties of the laser-cladded MSS coatings have been carefully investigated. The results show that the original Nb-free MSS coating is mainly composed of martensite and austenite, along with nano-M2N and M23C6. With the addition of Nb, the lath-shaped martensite is refined, and an increasing occurrence of nano-sized Nb-enriched precipitates (NbC and Nb(C,N)) is observed in the coatings with increasing Nb content. With the successive addition of Nb, the microhardness of the specimens is found to increase from the 437 HV0.2 of the Nb-free coating to the 502 HV0.2 of the 1.0 wt% Nb-alloyed coating. At the same time, the tensile mechanical properties and corrosion resistance are found to increase with increasing Nb content of up to 0.5 wt% and subsequently decrease with further addition of Nb. Thus, the addition of 0.5 wt% Nb provides a laser-cladded MSS coating that is superior to those reported in the literature, combining the optimum tensile properties of high strength (1780 MPa) and high ductility (EL = 10.5%) along with excellent corrosion resistance. The remarkable overall properties of the as-prepared MSS coatings can be ascribed to the combined effects of solid solution, microstructural refinement, and nano-precipitation.

Effect of Bond-Layer on the Wear Resistance of a Martensitic Stainless Steel Coating Obtained by Wire Arc Spray

Effect of Bond-Layer on the Wear Resistance of a Martensitic Stainless Steel Coating Obtained by Wire Arc Spray

Influence of Vanadium Microalloying on Microstructure and Property of Laser-Cladded Martensitic Stainless Steel Coating.

Martensitic stainless steel (MSS) coatings with different vanadium (V) contents (0–1.0 wt%) by microalloying have been successfully fabricated utilizing a unique laser cladding technique. The microstructure and properties of the resulting MSS coatings, with and without element V addition, have been carefully investigated by various advanced techniques, including XRD, SEM, TEM, microhardness tester, universal material testing machine, and electrochemical workstation. It was found that the V-free coating was mainly composed of martensite (M) and ferrite (F), trace M23C6 and M2N, while the V-bearing coatings consisted of M, F, M23C6, and VN nano-precipitates, and their number density increased with the increase of V content. The V microalloying can produce a significant impact on the mechanical properties of the resulting MSS laser-cladded specimens. As the V content increased, the elongation of the specimen increased, while the tensile strength and microhardness increased firstly and then decreased. Specifically, the striking comprehensive performance can be optimized by microalloying 0.5 wt% V in the MSS coating, with microhardness, tensile strength, yield strength, and elongation of 500.1 HV, 1756 MPa, 1375 MPa, and 11.9%, respectively. However, the corrosion resistance of the specimens decreased successively with increasing V content. The microstructure mechanisms accounting for the property changes have been discussed in detail.

Laser cladding and in-situ nitriding of martensitic stainless steel coating with striking performance

The nitrogen (N) alloying in traditional bulk martensitic stainless steel (MSS) necessitates high-pressure and high-temperature treatment because of its extremely low solubility. Herein, we report a novel strategy for in-situ nitriding MSS coating with N content up to 0.14 wt% by laser cladding technique without harsh conditions. The resulting coating is composed of martensite, austenite, nano-precipitates M23C6 and M2N, which exhibits striking mechanical properties with tensile strength of 1900 MPa and elongation of 7.3% as well as excellent corrosion resistance, exceptionally superior to the reported laser cladded MSS coatings. This may be ascribed to the combination impacts of grain refinement, nano-precipitation, interstitial solid solution and dislocation strengthening.

Effects of Low-Temperature Tempering on Microstructure and Properties of the Laser-Cladded AISI 420 Martensitic Stainless Steel Coating

Post-treatment is crucial to improve the comprehensive performance of laser-cladded martensitic stainless steel coatings. In this work, a low-temperature tempering treatment (210 °C), for the first time, was performed on the laser-cladded AISI 420 martensitic stainless steel coating. The microstructure and properties of the pre- and post-tempering specimens were carefully investigated by XRD, SEM, TEM, a micro-hardness tester, a universal material testing machine and an electrochemical workstation. The results show that the as-cladded AISI 420 stainless steel coating mainly consisted of martensite, austenite, Fe3C and M23C6 carbides. The phase constituent of the coating remained the same, however, the martensite decomposed into finer tempered martensite with the precipitation of numerous nano-sized Fe3C carbides and reverted austenite in the as-tempered specimen. Moreover, a slight reduction was found in the micro-hardness and tensile strength, while a significant increase in elongation was achieved after tempering. The fractography showed a transition from brittle fracture to ductile fracture accordingly. The as-tempered coating exhibited a striking combination of mechanical properties and corrosion resistance. This work can provide a potential strategy to enhance the overall properties of the laser-deposited Fe-based coating for industrial applications.

The Study of Electroless Ni-P/Ni-B Duplex Coating on HVOF-Sprayed Martensitic Stainless Steel Coating

The Study of Electroless Ni-P/Ni-B Duplex Coating on HVOF-Sprayed Martensitic Stainless Steel Coating

Effect of Vanadium and Niobium on Abrasive Behaviour of Arc Sprayed 4Cr13 Coatings

4Cr13 martensitic stainless steel coatings with different amount of V/Nb were prepared on the surface of the Q235 low-carbon steel by high velocity arc spraying (HVAS). The microstructure and properties of the coatings were characterized and tested by scanning electron microscope (SEM), X-ray diffraction (XRD), optical microscope, microhardness tester and wear tester. And the wear mechanisms of the coatings have been studied. The results showed that optimal percentage of V/Nb could improve performance of the coatings. The coatings had good forming properties, uniformity of microstructure and compact structure.The highest value of adhesion strength was up to about 36.80 Mpa. The hard particles could incease the hardness and wear resistanc of the coatings.The average microhardness was about 523 HV0.1, higher than that of 4Cr13 coatings, and the abrasive wear resiatance was enhanced because of the added elements V and Nb. Key words: alloying coatings; 4Cr13; V/Nb; high velocity arc spraying (HVAS); abrasive behaviour

Wear and corrosion performance of AISI 410 martensitic stainless steel coatings produced using friction surfacing and manual metal arc welding

AISI 410 martensitic stainless steel coatings were produced on low carbon steel plates using friction surfacing and manual metal arc welding processes. Microstructure evolution in these coatings was investigated. Dry sliding pin-on-disk wear tests and electrochemical corrosion tests (Tafel and potentiodynamic anodic polarization) were conducted on friction surfaced coatings and manual metal arc coatings in as-deposited condition. Tests were also conducted on alloy 410 bulk material in hardened and tempered condition for comparison. Friction surfaced coatings, which contained a fully martensitic microstructure, showed comparable wear and corrosion resistance to alloy 410 bulk material. On the other hand, manual metal arc coatings, which contained significant amount of δ-ferrite, showed considerably lower hardness, pitting corrosion resistance, and wear resistance compared to friction surfaced coatings.

The effect of cladding speed on phase constitution and properties of AISI 431 stainless steel laser deposited coatings

Shorter processing time has given impetus to laser cladding technology and therefore in this research the AISI 431 martensitic stainless steel coatings are laser deposited at high cladding speeds, i.e. up to 117 mm/s. The analysis of phase constitution and functional properties of the coatings are performed by optical microscopy, Scanning Electron Microscopy (SEM), and hardness and sliding wear tests. The outcome of this research shows that an extreme refinement of the solidification structure will influence the phase constitution of the coatings by lowering the M s temperature and hence stabilizing the austenite which results in lower hardness values and increased wear rates. These results confirm that the structural refinement obtained by higher cladding speeds is not helpful for improving the hardness and wear properties of laser deposited martensitic stainless steel coatings.

Microstructural characterization of AISI 431 martensitic stainless steel laser-deposited coatings

High cooling rates during laser cladding of stainless steels may alter the microstructure and phase constitution of the claddings and consequently change their functional properties. In this research, solidification structures and solid state phase transformation products in single and multi layer AISI 431 martensitic stainless steel coatings deposited by laser cladding at different processing speeds are investigated by optical microscopy, Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), orientation imaging microscopy (OIM), ternary phase diagram, Schaeffler and TTT diagrams. The results of this study show how partitionless solidification and higher solidification rates alter the microstructure and phase constitution of martensitic stainless steel laser deposited coatings. In addition, it is shown that while different cladding speeds have no effect on austenite–martensite orientation relationship in the coatings, increasing the cladding speed has resulted in a reduction of hardness in deposited coatings which is in contrast to the common idea about obtaining higher hardness values at higher cladding speeds.

Plasma-spray-quenched martensitic stainless steel coatings

Plasma spraying was employed to form coating with the characteristics of liquid-quenched alloys. To achieve ultrarapid quenching (i.e. splat cooling) of the type 431 stainless steel alloys, melt-atomized powder was plasma sprayed onto copper substrates cooled with liquid nitrogen (LN). Three different quenching conditions were employed, including continous coverage of the substrate with a flowing film of LN, and quenching into LN intermittently during the actual spray coating process. Transmission electron microscopy was employed to analyze the sprayed coatings, and their adhesion and microhardness were determined. It was found that increased quench rates give rise to finer grain and second-phase distributions as well as a tendency toward cubic and austenite phases. Increased quench rates resulted in both enhanced microhardness and tensile adhesion strength. The underlying reasons for these effects will be discussed.