High-productivity multiple-wire submerged-arc welding and cladding with metal-powder addition

Aluminium metal is avoided as main reactant in submerged arc welding (SAW) because it is easily oxidised in this process. Aluminium is an effective de-oxidiser and can be used to prevent Cr and Co loss to the slag by preventing oxidation of these metals. In our novel application of aluminium metal powder in SAW we demonstrate the modification of flux oxygen behaviour. The Co-Cr-Al-alloyed weld metal total oxygen content is decreased to 180 ppm O, compared to 499 ppm O in the weld metal from the original flux, welded without metal powder additions. The flux oxygen behaviour is modified by the added aluminium powder through the lowering of the original flux-induced partial oxygen pressure in the arc cavity and at the molten flux-weld pool interface. Carbon steel was alloyed to 5.9% Co, 6.3 % Cr and 5.1% Al at 81% Co yield, 87% Cr yield and 70% Al yield. Gas-slag-alloy thermochemical equilibrium calculations confirm the partial oxygen-pressure-lowering effect of aluminium. BSE (backscattered electron) images of the three-dimensional (3D) post-weld slag sample show dome structures which contain features of vapour formation and re-condensation. These features consist of small spheres (sized less than 10 μm) and smaller needle-shaped particles coalescing into a porous sphere. EDX analyses show that the spheres consist of Si-Na-K-Fe-Mn-Co-Cr oxy-fluoride and the needles consist of low oxygen Si-Al-Ca-Mg-Na-K-Fe-Mn-Co-Cr oxy-fluoride. The element distribution and speciation data from the EDX analyses confirm modification of the flux oxygen behaviour via aluminium powder addition in lowering the partial oxygen pressure, which in turn prevents oxidation of Cr and Co and minimise losses to the slag.

The effect of different metal powder additions on the transport current and stress/strain performance of ex‐situ processed MgB2 tapes with Ni sheath has been studied. The metal powder added to the core exhibits elongated morphology after the fabrication. The addition of low melting point metal powder, e.g. In and Sn, produces an appreciable increase in the Jc of MgB2 core. An addition of 10 vol% In enhances Jc by a factor of 6 to 7 after the combination of rolling and annealing at 200 °C, up to the order of 105 A/cm2 at 0.5 T and 4.2 K. An addition of 10 vol% Sn enhances Jc by a factor of ∼ 3. The In and Sn additions also appreciably increase the n‐value of the current‐voltage transition. Both In and Sn metals infiltrate into gaps between MgB2 grains, improving the linkage of the grains. Current may transfer through the impregnated metal by the proximity effect. Furthermore, the metal powder addition appreciably improves the strain tolerance in MgB2 tapes. The low melting point metal powder addition is a relatively simple and easy approach to yield better transport current and stress/strain performance in ex‐situ MgB2 tapes.

In order to ensure good quality joints between aluminum sheets by resistance spot welding, a new approach involving the addition of metal powder to the faying surfaces before resistance heating is proposed. Three different metal powders (pure aluminum and two powders corresponding to the alloys AA2024 and AA7075) are investigated for the resistance spot welding of AA1050 aluminum sheets of three different thicknesses. Microstructural and mechanical analysis demonstrates that significant improvement in weld bead morphology and strength are obtained with the addition of metal powder. The improvement obtained is shown to be due to the development of a secondary bond in the joint beside the weld nugget increasing the total weld area. The application of powder additive is especially feasible, when using welding machines with insufficient current capacity for producing the required nugget size. In such cases the best results are obtained with pure aluminum powder.

Structure and critical current of Ni-sheathed PIT MgB 2 tapes with In metal powder addition

Advancements in understanding the microstructure and properties of additive manufacturing Ti-6Al-4V alloy: A comprehensive review

An EERZ (effective equilibrium reaction zone) model was applied to the modified SAW (submerged arc welding) process to simulate the SAW process metallurgy in the gas-slag-metal reaction system. The SAW process was modified by adding Al as a de-oxidizer with alloying metal powders of Cr, Cu, and Ti. The static gas-slag-metal equilibrium model can accurately calculate the weld metal oxygen content (ppm O) for conventional SAW but not for the modified SAW process. The static equilibrium model overpredicts the reaction of Al. EERZ model runs were made for 2000–2500°C because this is the reported temperature range in the SAW arc cavity. The weld metal composition was adequately calculated, especially the weld metal ppm O, at the following effective equilibrium temperatures: 2400°C for Al-Cr additions, 2200°C for Al-Cr-Cu additions, and 2000°C for Al-Cr-Cu-Ti additions. Model results show that Ti metal powder can serve a de-oxidizer role in the presence of Al, resulting in Ti loss to the slag. Ti is also lost to the gas phase as TiF3(g) and TiF2(g) compared to little loss of Cr to the gas phase as Cr(g) and CrO to the slag phase.

Comparison of wear and corrosion resistance behaviour of LENS TM deposited SS 316L alloy and wrought alloy

Effect of boronizing on microstructure, high-temperature wear and corrosion behavior of additive manufactured Inconel 718

As a result of the analysis of domestic and foreign literature, various methods for producing alloyed metal powders are studied, in particular atomization of alloys, acquisition with calcium hydride, thermal diffusion saturation, carbonyl processes, electrolysis and synthesis of complex oxides with further reduction. As a result, it was found that all researched methods, except for the synthesis and subsequent reduction of complex oxides, are not suitable for producing maraging steel powders. Atomization is suitable for producing pure metal powders, production with calcium hydride is impractical because maraging steels contain metals with a low affinity for oxygen ܨ ,݅ܰ ,݁݋ܥ և ݋ܯ ,thermal diffusion saturation is not suitable due to the use of metal powder and the carbonyl process is rather complicated and difficult to implement. Comprehensive studies have shown that by combining the processes of synthesis (ferritation) and reduction of complex oxides in the best possible way, it is possible to develop an effective technology for production of alloyed powders, which will guarantee acquisition of an ultrapure chemical composition, required structure and properties.

Effect of shot peening and treatment temperature on wear and corrosion resistance of sequentially plasma treated AISI 316L steel

Abrasion easily occurs due to the characteristic of the usage environment such as oil sands and construction equipment, and the demand for a steel with excellent wear resistance is increasing in various industries where specific parts are frequently replaced. Recently, by controlling the amount of manganese, high manganese austenite steels with improved wear resistance and low temperature brittleness performance have been developed and widely applied to LNG fuel tanks of ships and pipes. In this study, the temperature distribution, residual stress, and weld deformation caused by welding generated by friction stir welding(FSW) and submerged arc welding(SAW) for high manganese austenite steel with strong wear resistance were analyzed through thermal elastic plastic analysis.

This study investigates the development of silver (Ag)-doped zirconia (ZrO2) coatings deposited on 316LVM stainless steel via the unbalanced magnetron sputtering technique. The oxygen content in the Ar/O2 gas mixture was systematically varied (12.5%, 25%, 37.5%, and 50%) to assess its influence on the resulting coating properties. In response to the growing demand for biomedical implants with improved durability and biocompatibility, the objective was to develop coatings that enhance both wear and corrosion resistance in physiological environments. The effects of silver incorporation and oxygen concentration on the structural, tribological, and electrochemical behavior of the coatings were systematically analyzed. X-ray diffraction (XRD) was employed to identify crystalline phases, while atomic force microscopy (AFM) was used to characterize surface topography prior to wear testing. Wear resistance was evaluated using a ball-on-plane tribometer under simulated prosthetic motion, applying a 5 N load with a bone pin as the counter body. Corrosion resistance was assessed through electrochemical impedance spectroscopy (EIS) in a physiological solution. Additionally, tribocorrosive performance was investigated by coupling tribological and electrochemical tests in Ringer’s lactate solution, simulating dynamic in vivo contact conditions. The results demonstrate that Ag doping, combined with increased oxygen content in the sputtering atmosphere, significantly improves both wear and corrosion resistance. Notably, the ZrO2-Ag coating deposited with 50% O2 exhibited the lowest wear volume (0.086 mm3) and a minimum coefficient of friction (0.0043) under a 5 N load. This same coating also displayed superior electrochemical performance, with the highest charge transfer resistance (38.83 kΩ·cm2) and the lowest corrosion current density (3.32 × 10−8 A/cm2). These findings confirm the high structural integrity and outstanding tribocorrosive behavior of the coating, highlighting its potential for application in biomedical implant technology.

In the present work, a low-carbon steel substrate was coated with Al2O3 and TiC using self-propagating high temperature synthesis. The synthesized coatings were annealed at 450 °C for 2–6 h. The characteristics of the substrate, coated, and annealed samples were examined, including microhardness, wear resistance, and corrosion resistance. A pin-on-disc tribometer was employed to conduct the wear test by varying the load, sliding velocity, and distance. The impact of these factors on the wear rate and worn surface morphology was then examined. Further, corrosion resistance was evaluated using electrochemical corrosion testing with 3.5 wt% NaCl as electrolyte. Results showed that Al2O3 and TiC specimens annealed at 450 °C for 5 h and 4 h improved the microhardness by 1.3 and 1.06 times than that of as-coated specimens respectively. The synthesized Al2O3 and TiC coatings showed an abrasive wear mechanism at higher loads and tribolayer formation was observed at higher sliding velocity and distances. The corrosion and wear resistances of the samples were found as follows: substrate< Al2O3 coated < TiC coated < Al2O3 annealed < TiC annealed. The Al2O3 and TiC ceramic coatings were found to improve wear and corrosion resistance having potential applications in cement, petrochemical, and marine industries.

Crucible CPM 420V is a unique tool steel made by the Crucible particle metallurgy (CPM) process. The alloy is designed from a martensitic stainless steel based analysis with added carbon and vanadium for exceptionally good wear resistance. CPM 420V offers significant improvements over CPM 440V in both wear and corrosion resistance. The exceptional wear resistance and good corrosion resistance of CPM 420V make it an excellent candidate to replace 440C and other corrosion- and wear-resistant materials, particularly where increased wear resistance is a primary concern. This datasheet provides information on composition, physical properties, hardness, and elasticity as well as fracture toughness. It also includes information on corrosion and wear resistance as well as heat treating and machining. Filing Code: SS-736. Producer or source: Crucible Service Centers.

Twelve pipe bombs were exploded, and the fragments were collected and weighed. The distribution of fragment masses was shown to follow a Weibull-type form M (n)=M0 [1 − exp (−Bnλ)] when RDX-based military explosives were used and a bimodal distribution when commercial explosives were used. The constant, B, was a function of the mass of fragments recovered, making its use inappropriate in a forensic context where complete collection of the fragments would not be possible. For RDX-based explosives with added Mg or Al powder, the value of the constant, λ, was reduced compared to that of the RDX-based explosive without metal powder additions. An alternative fragment distribution formula, log [(100 M (N))/M0]=FWDM [m(N)/ M0], can also be used to distinguish between explosives, although the correlation coefficient is inevitably somewhat lower and the scatter between the results of nominally identical tests can be greater. The coefficient, FWDM, has a dependence on the mass of fragments collected, restricting its utility in forensic contexts.