Clad Plate Research Articles

Evaluation and Prediction of Mechanical Properties According to Welding Methods of Ni 825/A516-70N Clad Plates

In this study, the microstructures and mechanical properties of different methods of FCAW (Flux-cored arc welding) + FCAW or FCAW + GTAW (Gas tungsten arc welding) welding on Ni825/A516-70N clad plate were investigated, using a double U groove angle on a laboratory scale. The amount of specimen deformation with FCAW + FCAW welding was ~1.5 mm, and that with FCAW + GTAW welding was ~3.6 mm. In the Vickers hardness tests, the average hardness value of the FCAW + GTAW welding specimens tended to be higher, and the hardness of the steel showed the same value. Also, in the tensile tests, the maximum strength and elongation of the FCAW + GTAW specimens were found to be higher. The SEM analysis of the welding boundaries of each specimen revealed the phenomenon of grain refinement in the specimens with FCAW + GTAW welding. This was due to the slow welding speed of this welding process and the rapid cooling rate caused by the relatively low layer thickness despite the relatively high number of weld passes. The computer simulation of the amounts of deformation were similar, with a value of 1.5 mm for FCAW + FCAW and 3.6 mm for the computer simulation, indicating the credibility of the simulation. In the computational simulation of butt welding, FCAW + GTAW showed high values for both residual stress and angular strain. The L-seam and C-seam of the demo vessel size were welded under the same conditions as the actual welding. The residual stress and angular deformation in the L-seam were 849 MPa and 2.3 mm for the FCAW + FCAW and 852 MPa and 2.9 mm for FCAW + GTAW. The residual stress and angular deformation in the C-seam were 920 MPa and 0.7 mm for FCAW + FCAW and 930 MPa and 0.9 mm for FCAW + GTAW, respectively.

Rolled Thickness Prediction for Titanium/Steel‐Clad Plates Based on Combined Method of Theoretical and Neural Network

To address the issue of low precision in rolled thickness prediction for titanium/steel‐clad plates, theoretical calculation and back propagation (BP) neural network prediction models are established based on the slab method and the rolled measured data, respectively. Furthermore, to solve the model's black‐box problem while also improving thickness prediction accuracy, three combined prediction models are built using the principles of compensating multiplicative error, additive error, and average error based on the model's advantages and features for thickness prediction. During the modeling phase, 1925 groups of manufacturing data for titanium/steel‐clad plate rolling are selected and normalized to form the data set. The trial‐and‐error method is used to determine the optimal network structure for the BP neural network. The model's performance is assessed by calculating the mean square error, mean absolute error, and coefficient of determination (R2) and comparing the relative errors in prediction outcomes across different models. In the results, it is demonstrated that the average error combined model (Combined Model III) performs better and predicts more accurately.

Effect of Pulse Current on Interface Microstructure and Bonding Properties of TA1/304 Double-Layer Clad plates

It is difficult to effectively improve the low bonding strength of TA1/304 clad plates. This study proposes a new process for applying pulse current (1500 A, 500 Hz, 50% duty cycle) to TA1/304 clad plates during the rolling process, which changes the interface microstructure and effectively improves the bonding strength of the clad plates. The influence of the pulsed current on the interface microstructure and bonding strength was systematically studied. The results indicate that the clad plate is initially bonded at 750 °C and 35% reduction ratio under electrically-assisted rolling (EAR), and finally the higher bonding strength is obtained at 850 °C and 48% reduction ratio, reaching 395 MPa. The strengthening of the interface element diffusion and grain refinement under the action of the pulsed current are important reasons for the improvement in the bonding strength of the clad plate. This discovery provides new ideas for the preparation of clad plates with high bonding performance.

Research on the bonding performance and mechanism of hot-rolled Ti/steel clad plates based on surface state

The interfacial bonding strength of Ti/steel clad plates is a crucial factor that affects their application. However, the effect of the surface state, which is a significant determinant, is often neglected. In this study, various surface treatment processes were employed to create different surface states based on the hot-rolling of double-layer steel billets, and the effects and mechanisms of these surface states on the bonding performance of hot-rolled Ti/steel clad plates were systematically examined. The results showed that the Ti/steel clad plates pretreated with a louver wheel exhibited the highest bonding performance, with the average bonding strength peaking at 328.67 MPa and stabilising at approximately 300 MPa. This strength was approximately 50 % greater than that achieved with wire brush treatment and significantly surpassed the results obtained with sanding belts and diamond grinding discs. The analysis of the surface properties and microstructural characteristics revealed that various surface treatments led to different levels of work hardening and lattice distortion at the surface, and the interface bonding strength depended on the degree of matching between these factors. Proper surface hardening can promote the transformation of lattice distortion energy into a diffusion-driving force of elements on both sides of the interface during rolling, enabling sufficient diffusion of elements on both sides of the interface and obtaining good interface bonding performance. A phenomenological prediction mechanism-based model was established to quantify the relationship between the surface state and the bonding strength. This study elucidats the mechanism by which the surface state of materials influences the interfacial bonding performance of hot-rolled Ti/steel clad plates. These findings have significant implications for enhancing the interfacial properties of these composite plates and for selecting suitable pre-rolling surface treatment processes.

Indentation parameters and corrosion resistance of explosive welded S30400/Q345R clad plates with heat treatment cycles

This study aims to clarify the indentation parameters and corrosion resistance of explosive welded S30400/Q345R clad plates with heat treatment cycles. A series of tests on the mechanical properties of the clad plate in the unseparated state of clad material (CM) and base material (BM) and its free surface corrosion resistance, as well as their evolution with stress relief heat treatment are studied and discussed. The results show that the severely carburised layer (SCL) that occurs on the stainless steel side of the heat treatment was the peak hardness of the entire clad plate, which was significantly reduced after four heat treatments. The worst mechanical performance was observed in three heat treatments. The reduction in free surface corrosion resistance of CM is linearly correlated with the number of heat treatments, but this does not hold true for BM. This study provides valuable references for the assessment of performance loss under heat treatment of clad plates.

Microstructure evolution and mechanical performance of roll-bonding interface in HAZ during arc welding of titanium/steel clad plates

Microstructure evolution and mechanical performance of roll-bonding interface in HAZ during arc welding of titanium/steel clad plates

Effect of Heat Treatments on the Microstructure and Mechanical Properties of SS317L/ASTM SA516 GR60 Steel Clad Plate Fabricated Through Hot Roll Bonding

Triple-layer stainless-steel clad plate having 317L stainless steel (SS317L) as cladding layer and ASTM SA516 GR60 (GR60) as backing layer was successfully fabricated through vacuum hot roll bonding (VHRB) at 1373 K (1100 °C) temperature and strain rate regime of 1–5 s−1, which were identified through process efficiency maps of the base materials (SS317L and GR60). The process efficiency maps were constructed by conducting isothermal compression tests within the temperature range of 1173 K (900 °C)–1473 K (1200 °C) and 0.1–50 s−1strain rate regime. Effect of post-rolling heat treatments on the mechanical properties of clad plate was studied after solutionization at 1173 K (900 °C) for 1 h followed by cooling at different rates, i.e., water quenching, air cooling, and furnace cooling. As compared to other post-rolling heat treatments, the ultimate tensile strength, uniform plastic elongation, and maximum shear strength showed a significant change from 524 MPa, 0.46 and 519 MPa to 652 MPa, 0.36 and 410 MPa, when the normalized clad plate was solutionized at 1173 K (900 °C) and water quenched. A drastic change in shear fracture mode from gradual failure in normalized condition to catastrophic failure was also noticed after water quenching. These changes are essentially manifestation of the microstructural change in GR60 layer which led to the change in mechanical properties.

Research status and application of 304/Q235 stainless steel clad plate

Research status and application of 304/Q235 stainless steel clad plate

Effect of annealing temperature on interfacial microstructure and tensile fracture behavior of titanium-steel clad plate

To ensure that the rolled composite plate has excellent processing properties. Annealing is an effective means of modulating organization and mechanical properties. In this study, annealing treatments at different temperatures were applied to the rolled titanium-steel clad plate. The evolution of the interfacial organization was observed using scanning electron microscopy. The strain distribution of the composite plate in the tensile process was investigated using a tensile experiment combined with the DIC method. The results indicate the presence of compounds such as TiC, Fe2Ti, and FeTi after hot rolling. As the annealing temperature increases, the thickness of the interlayer diffusion of elements between the two plates increases. The geometric dislocation generated between the grains after hot rolling is significantly improved after annealing treatment, and the geometric dislocation density decreases with the increase in annealing temperature. In the titanium layer, the titanium grains, after annealing at 550 °C and 600 °C, are in the recovery stage, and the amount of recrystallization does not change significantly. However, after annealing at 650 °C, the titanium grains are completely recrystallized, the grains are equiaxed, and the grain-to-grain anisotropy is eliminated. The sample annealed at 550 °C fractures almost simultaneously in the tensile test in the titanium layer and steel layer, with an elongation of 32.3% and a tensile strength of 477.1 MPa, showing the best comprehensive performance. Based on DIC strain curve analysis, The strain curve after annealing at 550 °C is smoother, the necking is relatively consistent, and it reaches a point of relatively consistent local strain instability.

Failure Mechanisms in Stainless Steel/Carbon Steel Clad Plate Under Shear Tensile Loading: Experimental and Modeling Methods

The deformation behavior of a stainless steel/carbon steel (SS/CS) clad plate under interface shear loading is characterized in this work. A 2D digital image correlation method is applied to track the strain field variation near the interface during shear tensile tests. Then, a cohesive zone model (CZM) finite‐element method is developed to clarify the delamination behavior of the tested clad plate. Finally, the interfacial failure characteristics of the SS/CS clad plate are further presented through the comparison between the finite‐element method and fractography analysis at the interface. In the experimental and simulation results, it is shown that the mixed‐mode CZM, which couples the constitutive equations of three fracture modes, demonstrates excellent capabilities in capturing SS/CS interfacial deformation behavior. The main deformation mode in shear tensile tests is variable according to locations. The central region at the bonded surface is dominated by the shear delamination mode, and the region near the notches shows shifted crack propagation toward normal mode. These abrupt interfacial failures can be clarified via stress state and local damage analysis of the well‐reproduced finite‐element model of cladding material.

High bonding strength of Ti /steel clad plates prepared by a developed electromagnetic induction heating followed by rolling

Titanium/steel clad plates exhibit significant potential for industrial applications, such as petrochemical and aerospace, due to their combined advantages of two components. In the conventional hot rolling process, the formation of brittle intermetallic compounds (IMCs) had a detrimental effect on the mechanical properties of Ti/steel clad plates. Therefore, the present study proposed an electromagnetic induction heating rolling (EIHR) technique for efficiently fabricating Ti/steel clad plates with high bonding strength at a relatively low temperature, while avoiding the formation of brittle IMCs. Additionally, a pure iron DT4 interlayer with good fluidity was introduced between Ti and steel, which can further enhance both the interface bonding strength and elongation of the clad plates. Based on the electron backscattered diffraction characterization results of the interface, it was found that the addition a DT4 interlayer facilitated dynamic recrystallization of steel side and led to a reduction in dislocation density. Moreover, a pronounced {100}〈011〉 rotational cube texture was evident on the (100) pole figures as a result of substantial plastic deformation during the rolling process. Finally, the relationship between interface microstructure and mechanical performance was established.

Interface enhancement mechanism of rolled Mg/Al clad plate with particle interface control

In this study, the cold-spraying process was utilized to deposit Al particles onto an Al slab, an Mg slab, and both Al and Mg slabs to form an ultra-thin interlayer, and then the clad slabs were rolled at 400 °C, developing three roll-bonding processes: the roll-bonding process with cold-sprayed Al powder on the Al slab (CS-Al), the roll-bonding process with cold-sprayed Al powder on the Mg slab (CS-Mg), and the roll-bonding process with cold-sprayed Al powder on both the Al slab and the Mg slab (CS-Both). The effects of three different cold-sprayed Al particle interlayer processes on the mechanical properties of rolled Mg/Al clad plates were investigated to improve the mechanical properties. The microstructure, texture evolution, intermetallic compound formation, mechanical properties, and mechanisms involved in the Mg/Al clad plate rolling were systematically investigated. The results showed that the pre-bonding between the particles and the substrates through cold-spraying had a significant impact on the bonding strength of the Mg/Al clad plates, and the CS-Both process can increase the average shear strength of the Mg/Al clad plates to 49.24 MPa at a medium reduction rate of 37.5 %, 2.5 times that of the conventional rolling process. The CS-Both process constructed more evident dual microscopic three-dimensional interfaces and promoted more thorough atomic diffusion at the interface through the double-sided cold-spraying process. Meanwhile, the dual cold-sprayed Al coatings on both the Mg slab and Al slab underwent dynamic recrystallization during rolling to form a homogeneous unit with no additional coating interfaces. Fine grain strengthening and dislocation strengthening were judged to be important mechanisms for improving the mechanical performance of the interfacial layer.

Fabrication of high strength-ductility aluminum alloy heterogeneous plates using additive manufacturing and hot rolling process

Aluminum alloy heterogeneous plate has great potential applications in automotive, military, aerospace, and other fields due to its excellent mechanical properties and ability to resist ballistic missile penetration. In the present work, a 5356/7A48 aluminum alloy heterogeneous plate with high strength-ductility and excellent interfacial metallurgical bonding strength was prepared using wire-arc additive manufacturing and hot rolling (WAAM+HR) process. The yield strength and ultimate tensile strength were 280.2 MPa and 392.3 MPa, respectively, both of which were between 5356 and 7A48 alloys, but the elongation was excellent, up to 22%. Its excellent comprehensive mechanical properties far exceed those of Al/Al heterogeneous plates reported in previous studies. In addition, compared with traditional clad plates, its fracture displacement is improved by 48.8%, showing remarkably high interlayer bonding strength. The soft layer 5356 and the hard layer 7A48 beared the main plastic strain and normal stress respectively, resulting in back-stress strengthening at the interlayer interface, which was the fundamental reason for the synergistic effect of strength and plasticity. Furthermore, even at the maximum bending angle of 180°, the heterogeneous plate did not show any sign of fracture, thanks to the fact that the outer soft-clad layer accommodated most of the bending deformation. The heterogeneous lamella structure, high constraint of hard layer to soft layer, and high geometrically necessary dislocations (GNDs) density of interfaces effectively stimulated the back stress strengthening and dislocation hardening, so that the 5356/7A48 aluminum alloy heterogeneous plate exhibited excellent comprehensive mechanical properties. The proposed WAAM+HR process provides an approach for the preparation of multi-functional heterogeneous plates with high strength-ductility and superior bonding strength.

Single-pass high-power laser-Arc hybrid welding of thick stainless steel clad plates: Microstructure and mechanical properties

In order to solve the existing problem of low efficiency of multi-layer and multi-pass welding methods for thick stainless steel clad plate (SSCP), this paper proposes high-power laser-arc hybrid welding (HP-LAHW) single-pass weld thick SSCP. The effects of wire feeding rate (WFR) on the weld's composition distribution, microstructure and mechanical properties were investigated. The weld morphology is nail-shaped, consisting of a wide arc zone (ArcZ) within the stainless steel layer and a long narrow laser zone (LaserZ), mainly in the carbon steel layer. With the increase of WFR, the dilution rate of the carbon steel layer to the ArcZ decreases first and then increases. The influence of WFR on the microstructure and mechanical properties of the weld is observed mainly in the ArcZ. When the WFR reaches 6 m/min, the composition of the microstructure within the ArcZ will change from martensite, ferrite, and a small amount of granular austenite to ferrite and a small amount of austenite, resulting in the microhardness of the ArcZ decreasing rapidly from 398 HV to 210 HV. The solidification type and microstructure transformation mechanisms within the weld were elucidated based on quantitative calculations of the chromium and nickel equivalent ratios. The microstructure of the LaserZ in all welds is predominantly martensitic due to the rapid cooling rate, which makes the tensile properties of the weld higher than the base metal (BM). The results of this study provide technical support for realizing high-efficiency and high-performance single-pass HP-LAHW of thick SSCP.

Effect of Nb interlayer thickness on interfacial products and mechanical properties of Ti–6Al–4V/EH690 steel clad plate by vacuum hot rolling

The high content of alloying elements in Ti alloys and high-strength steels, combined with the requirement for quenching and tempering heat treatment during the fabrication process of the clad plate, leads to complex interfacial products and poor bonding properties. An Nb interlayer was introduced to enhance the mechanical properties of Ti alloy/steel clad plates. This work investigated the effect of Nb interlayers with initial thicknesses of 10, 25, and 50 μm on the evolution of interfacial products and bonding properties. The results indicated that when the interlayer was thin (10 μm thick), the diffusion of Ti, Fe, and C in the matrix and clad materials could not be completely inhibited due to the uneven distribution of the Nb interlayer at the interface. TiC, NbC, Nb2C, and Fe2Nb were detected at the Nb/steel interface. With the thickness of the interlayer increased (reaching 25 μm or 50 μm), the influence of uneven deformation on the interlayer was weakened, and the Nb/steel interface was composed of Nb2C and Fe2Nb. The tensile shear test indicated that the fracture occurred at the Nb/steel interface and the Nb interlayer. The plasticity of the micrometer Nb interlayer decreased with the increase in interlayer thickness. Therefore, more cracks and brittle fracture characteristics were observed in the fracture surface of the 50 μm thick Nb interlayer sample. The clad interface with a 25 μm thick Nb interlayer exhibited the highest interfacial shear strength of 295 MPa due to the few intermetallic compounds (IMCs) at the Nb/Steel interface and the excellent plasticity of the Nb interlayer.

Effects of size and static temperature exposure on the shear strength of tungsten bonded CFC blocks for divertor in JT-60SA

The construction of a satellite tokamak, JT-60SA, was completed in 2020. JT-60SA is expected to contribute the research of ITER and developments for DEMO. JT-60SA employs carbon and carbon fiber strengthened carbon (CFC) composites divertors. The divertors will be set on an actively cooled cassette and be remotely handled because of human access restriction into the vacuum vessel due to the radioactivation caused by repeated deuterium plasma operations. An important mission of JT-60SA is high-β steady state plasma research, and during the mission, the use of carbon divertors will be continued. The possibility of metal wall experiments after the complete of high-β steady state plasma research is under discussion. Then the use of remote handled divertor cassette will be a condition, therefore, high performance and appropriate weight divertors are convenient for the operation. One idea is to use clad plates of tungsten and CFC. In previous researches revealed that a sinter bonding method using an insert material of SiC powders + additives was able to join W and CFC. But the research accidentally found out the insert material without explore of the other materials and the size of specimens was small. In present research, some candidates for the insert material were investigated and also the uniformity of strength on a W/CFC block of the expected size were evaluated.

Effect of nano-AlN, Al2O3 on friction and wear properties of copper-steel clad plate immersed in the lubricants

PurposeThis paper aims to investigate the preparation of AlN and Al2O3, as well as the effect of nano-AlN and nano-Al2O3, on friction and wear properties of copper-steel clad plate immersed in the lubricants.Design/methodology/approachNano-AlN or nano-Al2O3 (0.1, 0.2, 0.3, 0.4 and 0.5 Wt.%) functional fluids were prepared. Their tribological properties were tested by an MRS-10A four-ball friction tester and a ball-on-plate configuration, and scanning electron microscope observed the worn surface of the plate.FindingsAn increase in nano-AlN and Al2O3 content enhances the extreme pressure and anti-wear performance of the lubricant. The best performance is achieved at 0.5 Wt.% of nano-AlN and 0.3 Wt.% of nano-Al2O3 with PB of 834 N and 883 N, a coefficient of friction (COF) of approximately 0.07 and 0.06, respectively. Furthermore, the inclusion of nano-AlN and nano-Al2O3 particles in the lubricant enhances its extreme pressure performance and reduces wear, leading to decreased wear spot depth. The lubricating effect of the nano-Al2O3 lubricant on the surface of the copper-steel composite plate is slightly superior to that of the nano-AlN lubricant, with a COF reaching 0.07. Both lubricants effectively fill and lubricate the holes on the surface of the copper-steel composite plate.Originality/valueAlN and Al2O3 as water-based lubricants have excellent lubrication performance and can reduce the COF. It can provide some reference for the practical application of nano-water-based lubricants.Peer reviewThe peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-08-2023-0255/

Research on microstructure and mechanical properties of TC4/304 clad plates by asymmetric rolling with local strong stress

In order to solve the problems of complex traditional preparation process and low bonding strength of titanium/steel clad plates, TC4/304 clad plates were prepared by asymmetric rolling with local strong stress (ARLSS), the effect of rolling temperature on the interface bonding of clad plates was studied. The two-dimensional simulation model of TC4/304 clad plates rolling was established by finite element method, and its accuracy was verified by experiments. The experimental results show that the interfacial bonding strength of the clad plates increased with the increasing temperature, but when the temperature reached 950 °C, the brittle intermetallic compounds (IMCs) formed extremely fast, which greatly weakens the bonding strength. The clad plates showed the best bonding strength at 900 °C. After corrugated roll bonding (CRB) (33 % reduction ratio), the bonding strength at the peak was lower than that at the trough. After FRB (46 % reduction ratio), the interface bonding strength was slightly improved. The final peak bonding strength reached 519 MPa, and the trough bonding strength was 527 MPa. The improvement of bonding strength mainly came from the improvement of TC4 matrix strength. The finite element simulation results showed that multiple cross shear zone in the deformation zone of the CRB stage were beneficial to the bonding of dissimilar metals. While the deformation of the clad plates material in the FRB stage was consistent, which effectively avoided the cracking of the bonded area and further improved the bonding strength. Therefore, the strong non-uniform plastic deformation of ARLSS process had a significant effect on the deformation coordination of dissimilar metals and the quality improvement of clad plates.

A novel B4C/Al-316 L neutron absorbing clad plate prepared by cold spraying: Microstructure and mechanical properties

Due to the excellent mechanical properties and neutron shielding properties, B4C/Al composites have become the most commonly used neutron absorbers. However, there is a problem of mutual restriction between the B4C content and mechanical properties (at high temperature) in B4C/Al composites. Therefore, for a B4C/Al-316 L clad plate prepared by cold spraying and subsequent annealing, it was proposed that the 316 L substrate will bear the mechanical properties at the high temperature required by the material, while B4C/Al composites will be used for neutron absorption. The neutron shielding performance of the B4C/Al composites was evaluated by Monte Carlo approach. EBSD tests were performed to characterize the microstructure, and a series of tensile and shearing tests were carried out to characterize the mechanical properties of the B4C/Al-316 L clad plates. The results revealed that the B4C/Al-316 L clad plates have good neutron absorbing qualities and excellent mechanical properties at room temperature and high temperature. In addition, the fracture mechanism of B4C/Al composites on B4C/Al-316 L clad plates was analyzed.

Effect of annealing on microstructure and mechanical properties of Mg/Al clad plate

Mg/Al clad plate was prepared by a combined process of corrugated roll rolling, flat roll rolling and annealing. The results show that the grain refinement is obvious in the first corrugated roll rolling, the grain grows before the second pass annealing, and the grain refines again after the second pass flat roll. By increasing the annealing temperature, the grain growth is promoted, the hardness of Mg17Al12 compound layer is 1.378–2.812 GPa, and that of Al3Mg2 compound layer is 1.161–1.281 GPa, which is higher than that of base metal. The mechanical properties of clad plate in transverse direction (TD) are better than those in rolling direction (RD). The residual stress can be eliminated by annealing, and the mechanical properties of clad plate can be improved.