Clad Plate Research Articles

Interfacial bonding characteristics and mechanical properties of H68/AZ31B clad plate

Interfacial bonding characteristics and mechanical properties of H68/AZ31B clad plate

The Microstructure and Property of a Titanium-Carbon Steel Clad Plate Prepared Using Explosive Welding

The microstructure and properties of pure titanium (Ti)-carbon steel clad plate prepared using explosive welding were characterized. The bonding of the welding interface was inspected using C-scanning imaging technique. The microstructure and composition of the clad were characterized with optical microscopy and scanning electron microscopy. Mechanical and corrosion properties of the clad plate were investigated using tensile test, shearing test, and potentiodynamic polarization measurement. The results show that the pure titanium and carbon steel plate are joined successfully without visible defects. The interface wave is uniform. SEM observation and EDS analyses show that some melt blocks distribute at the interface waves vortices. Hardness testes results show that after heat treating, the hardness values in the titanium layer of the clad plate are similar to the original titanium plate, whereas the values at carbon steel layer increase from the interface to 300 μm away. Tensile and shearing test results indicate that the mechanical properties of the clad meet the requirements of ASTM B898 standard. Corrosion test shows that the Ecorr of the clad plate is more positive, and icorr is 1 order of magnitude lower compared to carbon steel material, suggesting that the corrosion resistance of clad plate is better than that of carbon steel material. These results suggest that the clad plate has good bonding quality and properties to meet the processing requirement and can be safely applicable in the petrochemical field.

Improving mechanical properties of an explosive-welded magnesium/aluminum clad plate by subsequent hot-rolling

As-explosive welded clad plates usually show poor ductility due to heavily deformed microstructures developed after explosive welding (EXW). In this study, the feasibility of improving mechanical properties of an EXWed Mg–6Al–1Zn–1Ca (AZX611)/Al–0.6Mg–0.6Si–0.1Fe (A6005C) (all in wt%) clad plate has been explored by subsequent hot-rolling. Increasing the thickness reduction per pass from 10% to 28% or decreasing the rolling temperature from 430 °C to 250 °C is shown to enhance tensile properties. The joint sheet rolled at 250 °C with a thickness reduction per pass of 28% shows a large fracture elongation of 15%, which is significantly higher than that of the as-EXWed clad plate, 1.2%. Microstructure characterization by means of scanning electron microscope, electron backscatter diffraction and transmission electron microscope reveals that the substantial improvement in ductility is intimately related to a significant reduction of the accumulated strain in AZX611 and A6005C alloy sheets and an elimination of the interface delamination formed during EXW. A certain degree of anisotropic mechanical properties is observed in all sheets regardless of rolling conditions, which can be ascribed to the mechanical anisotropy originated from the AZX611 and A6005C alloy sheets.

Microstructure and coordination mechanism of interface of stainless steel/carbon steel cladding plate prepared by vacuum diffusion bonding

Vacuum diffusion bonding (VDB)-prepared 304 austenite stainless steel (SS)/Q235 carbon steel (CS) clad plates were the focus of this study. Specifically, the metallurgically bonded interfaces, which are known to have good mechanical properties, were investigated. The microstructures of the interfaces were extensively investigated using transmission electron microscopy (TEM). The characterization results revealed the existence of annealing twins and lath martensite precipitates at the interface; the high strength and plasticity at the interface were determined to be attributed to these features. In addition, the distribution and Burgers vector of dislocations at the ferrite–austenite interfaces were investigated by using two-beam method of TEM electron diffraction contrast image (EDCI) technology and high-resolution TEM imaging. As a result, the coordination mechanisms at the ferrite–austenite interfaces during the deformation of the SS/CS clad plates were clarified; the observations include: (1) the perfect dislocation with the Burgers vector a2⟨111⟩ in the ferrite moved across the interface and formed a perfect dislocation with the Burgers vector a2⟨110⟩ in the austenite; (2) the ferrite lattice was joined to the perfect dislocation with the Burgers vector a2⟨110⟩ in the austenite; and (3) the ferrite lattice continuously extended across the interface, and was connected to the austenite lattice. According to the results on the Burgers vector of dislocations, two types of dislocation reactions occurred at the ferrite–austenite interfaces during the deformation. Lastly, the transfer matrix of the orientation relationship (OR) between austenite and ferrite was calculated. The results revealed that the OR differed from that of the conventional OR between body-centered cubic and face-centered cubic structures; thus, it can be concluded that the preparation of SS/CS clad plates via VDB technology may lead to the formation of a unique OR between ferrite and austenite.

Long-term oxidation behaviour and thermal stability of heat-resistant stainless steel claddings deposited on AISI 316 stainless steel by the GTAW process

In the present study, the microstructure, oxidation behaviour, and thermal stability of the ER310 and ER446 weld overlay claddings deposited on AISI 316 stainless steel by the gas tungsten arc welding (GTAW) process were investigated. In this regard, the chemical composition, microstructure, and phase composition of the weld metals were characterized by optical microscopy (OM), field-emission scanning electron microscopy (FESEM-EDS), and X-ray diffraction (XRD) analysis. The oxidation behaviour and the bonding state of the clad plates were evaluated and compared after 1500 h of oxidation at 1000 °C using the isothermal oxidation and shear strength tests. Cross-sectional microstructural observations revealed that the substrates and weld overlay claddings were well bonded, and dense and uniform cladding layers without pores, cracks, or discontinuities were achieved. The weld metal produced by ER310 filler wire exhibited a completely austenitic microstructure, while the weld overlay produced by ER446 filler wire showed a ferritic-martensitic two-phase microstructure. The shear strength test results indicated that the bond strength of the ER446/AISI 316 and ER310/AISI 316 interfaces in the as-welded and oxidized conditions was higher than the minimum value (140 MPa) stated in the ASTM A264 standard. It was found that the oxidation process did not significantly reduce the bond strength of the interfaces. The weight gain data showed that both weld overlay claddings follow the parabolic rate law of oxidation, improving the oxidation behaviour of the AISI 316. The ER446 weld overlay had a lower parabolic rate constant (k p ) than the ER310 weld overlay. The SEM images showed that the oxide scales formed on the weld overlay claddings mainly consisted of three layers; Si-rich oxide at the innermost layer, Cr-rich oxide in the middle layer, and spinel oxide at the outer part of the scale. The oxidation behaviour of the clad samples was explained by the diffusion coefficients of elements, thermal stresses, and growth stresses, which are all associated with the matrix structure. • Heat-resistant stainless steel claddings were deposited on the surface of AISI 316 stainless steel using the GTAW process. • Thermal stability and oxidation behavior of the claddings after 1500 h of isothermal oxidation at 1000 °C were investigated. • The ER446 overlay displayed a ferritic-martensitic, while the ER310 overlay exhibited a fully austenitic microstructure. • The clad plates in the as-welded and oxidized conditions had a strength higher than the minimum value stated in ASTM A264. • Both ER446 and ER310 weld overlay claddings were improved the oxidation behaviour of the substrate.

Corrosion behavior of Cu/Al casting-rolled clad plates in different alkaline solution

The effect of pH value and different kinds of anions on the corrosion behavior of Cu/Al casting-rolled clad plates in the alkaline solution was evaluated by means of scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), weight loss analysis, 3D confocal laser scanning microscopy (CLSM) and electrochemical test. Results show the corrosion mainly occurs on the aluminum side. The corrosion resistance of the Cu/Al decreases as the pH value increases. When pH≥12, the dissolution of the film layer is faster than the passivation process. The addition of Cl− ions reduces the corrosion resistance of the Cu/Al clad plates, which leads to pitting corrosion. The higher the concentration of Cl− ions, the more prone the pitting to occur. The addition of SO42− ions causes the denudation of the samples. The corrosion resistance of the Cu/Al is better in the alkaline solution containing NO3− ions than that in the solution containing Cl− ions or SO42− ions. When adding SO42−, NO3− and Cl− to the pure alkaline solution, the corrosion resistance of the Cu/Al clad plates decreases.

Barrier Verification and Numerical Simulation of Vacuum Coating on Fe-Co-Ni Interlayer of Stainless Steel Clad Plates

Barrier Verification and Numerical Simulation of Vacuum Coating on Fe-Co-Ni Interlayer of Stainless Steel Clad Plates

Interface Characteristics and Bonding Performance of the Corrugated Mg/Al Clad Plate.

In this paper, a corrugated Mg/Al clad plate was successfully manufactured by an upper corrugated roller and a lower flat roller at 400 °C rolling temperature and 35% reduction ratio. Interface bonding performance of the corrugated Mg/Al clad plate was studied by tensile-shear test. The finite element method was used to simulate the corrugated rolling process. Experiment results revealed that the Mg/Al clad plate fabricated by corrugated roller had a tight bonding interface, no crack, and no intermetallic compounds. The transverse tensile-shear strength at the trough position reached 31.22 MPa, and the tensile-shear strength at the peak position was 17.61 MPa. It can be found that the stress and strain of interface metal at the trough position were the largest through numerical simulation results. Two cross-shear zones can be formed in the rolling deformation zone of the corrugated Mg/Al clad plate, which can accelerate the metal plastic flow and promote interface close bonding.

Bonding process and mechanisms of interface evolution of stainless steel clad plates fabricated by cyclic phase transformation heat treatment

Stainless steel clad plates have been largely used in engineering applications because of their excellent mechanical properties. Thus, there are many kinds of composite processes to prepare stainless steel clad plates. In general, the temperature is one of the most important parameters in the bonding processes, which is studied as a constant value. In this work, a novel bonding process using cyclic phase transformation heat treatment was subjected to manufacture stainless steel clad plates. The results reveal that stainless steel clad plates are successfully bonded. The joining process of the composite interface can be divided into three stages: the appearance of long interface voids, the shrinkage of long interface voids, and the formation of the continuous austenite phase. Microstructural analyses suggest that recrystallization and element diffusion occur during the bonding. Compared with isothermal heat treatment, it is obvious that this process can avoid ferrite grain coarsening. Moreover, the joining efficiency can be improved significantly by accelerating the transformation of the ferrite to the austenite at the interface. The shear test demonstrates that the shear strength of stainless steel clad plates after cyclic phase transformation heat treatment is larger than that of isothermal heat treatment in the same bonding time. The dimples on the shear fracture surface also dramatically increase.

Gas shock waves in the gap between the base and cladding plates during explosive welding

A theoretical model for shock wave propagation was established to study the airflow in the gap between the base and cladding plates of explosive welding, and the gas shock wave channel effect between the base and cladding plates was proposed and explained by theoretical analysis and calculation. The results show that the channel effect can push up the tail of the cladding plate before the collision point of explosive welding, and then causes the welding energy of the plate tail to increase too high or the explosive on the plate tail to be pressed dead. Therefore, the channel effect in explosive welding is the primary reason for the failure or quality reduction of the tail welding of long and large clad plates. In addition, other simplified theoretical models were used to further analyze various factors influencing on the channel effect, like clad plate width, various shielding gases and explosive welding in coarse vacuum. The optimization principle of shielding gas for explosive welding was explained, and also the helium-shielded explosive welding of titanium/steel and aluminum/magnesium was processing as experimental verification. The theoretical foundation for the further development and research of gas-shielded explosive welding and vacuum explosive welding was built up in this paper.

Effect of pure iron interlayer on microstructure and properties of hot-rolled stainless steel clad plate

Experiments on vacuum hot-roll bonding stainless steel clad plates with pure iron interlayers of different thicknesses were conducted at rolling temperatures of 1000 °C, 1100 °C, and 1200 °C and reduction ratios of 30 %, 50 %, and 70 %, respectively, to reduce the formation of brittle compounds at the bonding interface and improve the mechanical properties of the clad plates. The effects of pure iron interlayers with thickness of 1–3 mm on the microstructure and properties of the clad plates subjected to different rolling processes were studied via optical microscopy, scanning electron microscopy, and tensile-shear and tensile tests. Results showed that the carbon chromium compound layer near the interface could seriously reduce the mechanical properties of the clad plates. The pure iron interlayer could also effectively prevent the diffusion of carbon elements in carbon steel to stainless steel and prevent the generation of carbon chromium compounds. At 1100 ℃, 2mm pure iron could effectively inhibit the formation of compounds and obtain good mechanical properties. The maximum elongation was 53.8 % at 50 % reduction, and the shear strength and tensile strength were 318.2 and 501.8 MPa, respectively. When the reduction was 70 %, the elongation decreased to 30 %, but the shear strength and tensile strength peaked at 392 and 641.3 MPa, respectively.

STUDY ON MECHANICAL PROPERTIES AND MICROSTRUCTURE OF 42CrMo4/NANOS-BA® HIGH-STRENGTH CLAD PLATES AFTER THE PROCESS OF HOT ROLLING AND TWO-STAGE HEAT TREATMENT WITH ISOTHERMAL TRANSFORMATION

The aim of the study was to develop a technology for welding non-weldable 42CrMo4 and NANOS-BA® steel grades in the process of hot rolling and two-stage heat treatment. As a result of physical experiments carried out in a line for semi-industrial simulation of the production of metals and their alloys (LPS) and additional heat treatment, a durable combination of 42CrMo4 and NANOS-BA® steels with high mechanical properties was obtained, including: Rp0.2 = 1036 MPa, Rm = 1504 MPa and A = 10.9%, without microscopically visible cracks and other discontinuities in the joined surface. The quality of the 42CrMo4/NANOS-BA® clad plates produced in this way was assessed on the basis of microstructure examination as well as bending, shear and tensile strength tests.

Preparation of Gr-Reinforced Cu Foil: A Challenge to Ultrathin Thickness

A layered Cu/Gr/Cu ultrathin foil via a one-step electrochemical route A layered structure has a better effect on improving performance of the graphene (Gr)-reinforced composites due to its unique two-dimensional structure and excellent properties. In this work, a novel “one-step” electrochemical route was proposed for synthesizing the Gr-reinforced ultrathin copper (Cu) foil with high performance. The process includes: 1) A loose graphene oxide (GO) membrane, was prepared by electrophoresis deposition (EPD), that allows Cu ions passing through; 2) According to the difference of Cu deposition potential on different substrates, a potential step was designed for electrodepositing Cu successively on both sides of the GO membrane, i.e., the bottom Cu layer forms under low over-potential, while the top Cu layer forms under high over-potential. The experimental results show that the foil thickness reaches to as thin as 4-5 μm, and the tensile strength is almost twice as large as that of pure Cu foil. This process is simple, controllable and possible mass production, and expected to further practical applications in fields of Cu clad plate, printed circuit board and lithium-ion battery cathode collector system for saving raw material and also the space. In addition, this work proposes a new idea for preparing the layered composites via electrochemical route. A Cu-(CNTs+Gr) composite ultrathin foil via electrodeposition The incorporation of nano-reinforcement, such as carbon nanotubes (CNTs) and graphene (Gr), into copper (Cu) matrix via electrodeposition is a promising method to improve its comprehensive property. However, the challenge is to achieve a uniformly suspended electrolyte with these reinforcements or surfactant due to their inferior dispersibility. In this work, we report a process to produce a kind of high performance Cu-(CNTs+Gr) composite foil by using hybrid self-dispersing reinforcement CNTs+Gr via a direct current (DC) electrodeposition, which further results in an ultrathin foil reach to the thickness as low as 4 μm. In this process, firstly, the precursor graphene oxide (GO) with amphipathicity acts as a surfactant-like substance and disperses CNTs uniformly through the π-π bonding in-between GO and CNTs in the copper sulfate electrolyte. Then, GO is reduced into Gr during electrodeposition, and the synergistic effects of CNTs and Gr play a key rule to improve the ultrathin Cu-(CNTs+Gr) composite foil’s properties, including tensile strength up to 436 MPa, inoxidizability and superior electrical conductivity. This work provides a possibility to have mass-production of Cu foil as thin as 4 μm in industry and broad applications in the future.

Formability and interface structure of Al/Mg/Al composite sheet rolled by hard-plate rolling (HPR)

How to improve the bonding ability and quality performance of heterogeneous plates has always been one of the difficult problems in the field of high-performance heterogeneous composite sheet forming and manufacturing. In this paper, a new manufacturing method of heterogeneous clad plate, hard plate rolling clad plate, is proposed. The hot rolling process of Al/Mg/Al composite slab with or without hard plate was studied. The results show that the shear stress in the rolling direction (RD) can be transformed into the compressive stress in the normal direction (ND), and then the welding pressure between different composite layers can be increased. This method can suppress the bending and edge crack defects and significantly improve the shape quality and forming ability. At the same time, through the study of the interface structure of the composite plate, it can be known that the metallurgical bonding can be achieved with a small reduction after adding the hard plate. Two clear layers of Al3Mg2 and Al17Mg12 intermetallic compounds appear at the Al/Mg interface. The thickness of the diffusion layer is significantly larger than that of the traditional hot-rolled clad plate, and the thickness of the diffusion layer can reach 38 μm when the reduction is 60%. The yield strength is 172.3 MPa and the elongation is 21.5%. To sum up, the hot rolling of hard-plate provides a new idea for the forming and manufacturing of high performance heterogeneous composite plate.

Effect of first pass rolling reduction ratio on the microstructure and mechanical properties of TA1/Q235B clad plates

In this study, the microstructure, the shear strength and Vickers-hardness of TA1/Q235B clad plates under different first pass rolling reduction ratio (FP3R) were investigated. The microstructure and bonding interface were analyzed by optical microscopy (OM), scanning electron microscopy (SEM). The Vickers-hardness and tensile shear strength were also detected. The result indicated a good bonding along the interface of the bonded with flat and smooth under different reduction ratio. The shear strength of the TA1/Q235B clad plate increases with the increase of reduction ratio which was 189 MPa at maximum. The maximum Vickers-hardness was approximately 198.7 HV. The thickness of Ti and Fe diffusion layer increases from 2.6 to 3.65 [Formula: see text]m and 2.1 to 3.3 [Formula: see text]m, respectively. TiC and Fe-Ti intermetallic compounds were formed at the bonding interface due to diffusion of Fe, Ti and C, causing micro-indentation at the interface to initiate cracking and diffusion, and reduced the bonding quality.

A brief review on welding of stainless steel clad plates: issues and future perspectives

A brief review on welding of stainless steel clad plates: issues and future perspectives

Interface-position-dependent structure evolution and mechanical behavior of corrugated cold rolled Cu/Al clad plate: experiment and simulation

Abstract Cu/Al corrugated clad plates were prepared by the novel corrugated cold roll bonding (CCRB) process to investigate the stress states, microstructures and mechanical behaviors of the corrugated clad plate adjacent to various corrugated interface positions by experimental and numerical simulation methods. The results show that the CCRB process induces multiple “cross shear” zones in the rolling deformation zone. This greatly accelerates the plastic deformation of Cu layer and significantly diminishes the deformation difference between Cu and Al dissimilar metals with a result of the reduced warpage amplitude. Also, the microstructure at different positions is obviously different due to the various stress states and deformations. Especially at positions III (trough) and IV (front waist), the elongated grains and fine equiaxed grains are formed under the severe plastic deformation and the shear stress. And the ultimate tensile strength achieves a maximum value of 209.25 MPa at position III (trough), and does the minimum value of 182.43 MPa at position II (back waist). The strength of the Cu/Al corrugated clad plate is affected by both the dislocation strengthening and grain boundary strengthening. When the plastic deformation is severe, the dislocation strengthening mechanism is dominant in Cu matrix, while the fine-grain strengthening mechanism in Al matrix.

Influence of welding sequence on residual stress evolution in Incoloy825/X52 bimetallic clad plate butt-welded joints

Residual stress controlling is crucial for the service security of weldments. In this work, experimental measurements and finite element method were integrated to study the influence of welding sequence imposed on residual stress distribution of Incoloy825/X52 bimetallic clad plate joints. And the residual stress evolution law inside bimetallic clad plate joints during multi-layer and multi-pass welding was clarified. Results showed that the highest residual stress concentration was always generated in the translation layer and its surrounding region once the base, transition and flyer seam layer were all finished welding no matter what sequence was adopted. Welding sequence did have a significant influence on peak value and areas of both internal and surficial high-stress region of bimetallic clad plate joint.

Tensile behavior of stainless steel clad plates with different cladding ratios

The stainless steel clad plate is a new type of composite material with high performance, which combines the advantages of the substrate and cladding material, showing good mechanical properties. Nevertheless, previous studies are still insufficient to support the design of it as structural members. In this paper, the monotonic tensile tests of 24 stainless steel clad plate coupons were carried out. The stress-strain curves of the stainless steel clad plate with different cladding ratios were obtained, as well as that of the substrate and cladding materials. Besides, the layered method was used to modeling the stainless steel clad plate in finite element analysis (FEA), which was proved to be valid. Based on the verified model, four sets of finite element models (FEM) were added to cover the cladding ratio that was not involved in the test. Finally, the relationship between the mechanical properties of the stainless steel clad plate and its cladding ratio was discussed according to the experimental and FEA results. Finally, it was found that the tensile mechanical properties of stainless steel clad plate are between the substrate and the cladding, and changed linearly with the cladding ratio. Besides, it was also found that the stainless steel clad plate shows obvious anisotropy in the small deformation stage, while the anisotropy gradually weakens with the strain increased.

Influence of the applied layer on the state of stress in a bimetallic perforated plate under two load variants

The paper presents the results of the analysis of the influence of the applied plate layer on the state of stress in the bimetallic perforated plate. The finite element method ANSYS program was used for numerical calculations. The paper presents the results of stress tests for a single-layer clad plate made of S355J2 steel and a bimetallic perforated plate consisting of layers made of S355J2 steel and titanium. In addition, the study presents the results of the research on the influence of the method of loading, i.e. the concentrated force P in the geometric center of the plate and the external pressure q on the entire surface of the plate, and the method of support, i.e. free support and fixed, on the location of stress concentration zones in the bimetallic circular perforated plate. It has been shown that the presence of a perforated layer in the plate reduces the value of the equivalent von Mises stress by a minimum of approximately 30% in the base (steel) layer.