Dissimilar Weld Joints Research Articles

Influence of the welding parameters on the weld metal mechanical heterogeneity of EP517 (Fe12Cr2NiMoWVNb) steel and 36NKhTYu (Fe36Ni12Cr3TiAl) alloy dissimilar welded joints

The article presents the results of assessing the effect of the welding speed and the displacement of the electron beam relative to the joint on the mechanical heterogeneity of the weld metal of dissimilar welded joints of EP517 (Fe12Cr2NiMoWVNb) steel and 36NKhTYu (Fe36Ni12Cr3TiAl) alloy. Aging curves are plotted for the weld metal of welded joints made at electron beam welding (EBW) speeds of 30 m/h and 120 m/h, as well as for the weld metal of the welded joint made at a speed of 30 m/h with various electron beam displacements. An assessment of the change in the mechanical heterogeneity of the weld metal was carried out by the change in the standard deviation of the hardness values, and metallographic studies were also carried out. It was found that a decrease in the EBW speed leads to a decrease in the standard deviation of the results of measuring the hardness of the weld metal after aging from 45 to 14 HV5 or from 18% to 6%. It was also found that an increase in the displacement of the electron beam to alloy 36NKhTYu (Fe36Ni12Cr3TiAl) to 60% leads to an increase in the hardness of the weld metal from 225 to 305 HV5 (by 35%).

Effect of Welding Groove and Electrode Variation to the Tensile Strength and Macrostructure on 304 Stainless Steel and AISI 1045 Dissimilar Welding Joint Using SMAW Process

AISI 1045 and 304 stainless steel are widely used in automotive and industrial fields However, both of these steels have their own advantages and disadvantages. AISI 1045 is not resistant to corrosion but has good wear resistance and low price. Meanwhile, the 304 stainless steel provides good corrosion resistance and mechanical properties but is costly. Their combination is able to provide a good property and reduce the costs. Thus, in order to combine these two metals, shield metal arc welding is carried out using welding groove and electrode variation. The groove variations used were double bevel, V, and double V-groove, additionally, the electrode variations used were E6013 and E7016. Then, the welding results were characterized using the tensile strength and macrostructure analysis. The results revealed that the specimen using E7016 electrode for the double V-groove resulted in the highest tensile test results the value of 270.48 MPa yield strength, 411.49 MPa tensile strength, and 19.81% elongation. The macrostructure analysis showed that the specimens using E7016 electrode gave a narrow HAZ that led to higher mechanical properties.

Dissimilar welding of high-entropy alloy to Inconel 718 superalloy for structural applications

High-entropy alloy, a new generation material, exhibits superior structural properties. For high-temperature applications, where dissimilar materials are in demand, HEAs may be joined with commercially available structural materials to improve their performance-life ratio. In this connection, a dissimilar joint was fabricated by gas tungsten arc welding between Al0.1CoCrFeNi-HEA and Inconel 718. The columnar dendritic grains are growing epitaxially at the Al0.1CoCrFeNi-HEA/weld metal interface, where their compositions are matching. While the composition misfit at the weld metal/Inconel 718 interface, reveals the non-epitaxial mode of solidification. In addition, the fusion zone exhibits the porosity and micro-segregation of NbC and Laves phases. The joint shows a joint efficiency of ~ 88%, where the strength is observed to be 644 MPa with 21% ductility. The results demonstrate the applicability of GTAW in fabricating the dissimilar weld joints between HEA and Inconel 718 for structural applications.Graphic abstract

Microstructural characterization of dissimilar weld joint between ferritic steel and stainless steel

In this investigation, microstructural variation across the dissimilar weld joint between modified 9Cr-1Mo ferritic steel and 316LN stainless steel with nickel-based filler metal was fabricated and characterized by various techniques. It was observed that the heterogeneous microstructure and non-uniform microhardness were developed across the dissimilar weld joint. Carbon-depleted soft zone, carbon-enriched hard zone, type I and type II boundaries are evident at the P91 heat-affected zone (HAZ) – buttering layer interface. An unmixed zone was observed at the weld metal-316 LN stainless steel HAZ interface. Distinct microstructures were developed across the dissimilar weld joint are due to the mismatch in chemical composition, crystal structure and melting temperature difference between base metals and filler metal.

Microstructure investigation on the fusion zone of steel/nickel-alloy dissimilar weld joint for nozzle buttering in nuclear power industry

Microstructure of the fusion zone of steel/nickel-alloy dissimilar metal welds (DMWs) for nozzle buttering was investigated by optical microscopy (OM), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and electron back-scattered microscopy (EBSD). The results showed that the dissimilar joint was complete, without welding defects. The structures of the fusion zone included the beach structure along the fusion boundary, the peninsula structures connected with the fusion boundary, and the island structures in the weld. The distribution of these three types of structures near the fusion boundary was uneven. The beach structure was formed because of the insufficient mixing and solidification of the molten liquid base material and the filler metal, with the width ranging between 0 and 150 μm. The peninsula and island structures were formed by the undercooling of the insufficiently mixed liquid base material and filler metal that entered the weld because of the convection and scouring of the weld pool. The composition of the three structures depended on the degree of mixing of the liquid base material and the filler metal, with a dilution ratio between 40 and 60%. The degree of dilution for the beach, peninsula, and island structures decreased in turn. With an increase in the dilution ratio, the initial solidification temperature of the corresponding composition increased significantly. When the dilution ratio exceeded 94.5%, the initial solidification phase transformed from the face-centered cubic γ-austenite into a body-centered cubic ferrite, with island structures solidified in the form of ferrites in the weld near the fusion boundary. The austenite grain orientations at weld side are dispersed with 75% large (> 15°) misorientation in frequency and the overall texture orientation distributes dispersedly with deviating from the < 100 > direction.

Improvement of Probabilistic Fracture Mechanics Analysis Code PASCAL-SP Regarding Stress Corrosion Cracking in Nickel Based Alloy Weld Joint of Piping System in Boiling Water Reactor

Abstract In the past few decades, cracks because of stress corrosion cracking (SCC) have been detected in the dissimilar weld joints using nickel-based alloy in piping system of boiling water reactors (BWRs). Thus, the structural integrity assessment for such weld joints has become important. Nowadays, probabilistic fracture mechanics (PFM) analysis is recognized as a rational method for structural integrity assessment because it can consider inherent uncertainties of various influencing factors as probability distributions and quantitatively evaluate the failure probability of a cracked component. The Japan Atomic Energy Agency has developed a PFM analysis code PASCAL-SP for a weld joint of piping system in nuclear power plant. This study improves the analysis functions of PASCAL-SP for weld joint using nickel-based alloy in BWR susceptible to SCC. As an analysis example of the improved version of PASCAL-SP, the failure probability of a weld joint is quantitatively evaluated. Furthermore, sensitivity analyses are conducted concerning the effect of leak detection and in-service inspection. From the analysis results, it is concluded that the improved version of PASCAL-SP is useful for structural integrity assessment.

Microstructural features and mechanical properties of similar and dissimilar ferritic welded joints for ultra-supercritical power plants

The grade P91 and P92 steel are commonly used materials for the components in ultra-supercritical power plants in the temperature range of 590–650 °C. For welded joints, the notch toughness and microstructure stability played an essential role in meeting the requirement of high temperature creep properties. The microstructural stability and notch toughness were strongly affected by the composition of base and filler materials, welding processes and pre and post-weld heat treatments (PWHTs). In the present research, four different combinations of similar/dissimilar welded joints of P91 and P92 steel are prepared using shielded metal arc welding (SMAW). The microstructure of different welded joints has been characterized in the as-welded condition. For the as-welded state, the room temperature tensile properties, flexural strength, microhardness and notch toughness have been studied. The δ-ferrite patches were observed for P92 filler welded joints. It has been concluded that in the weld fusion zone, the higher amount of ferrite stabilizers promotes the formation of the δ ferrite. The tensile strength and flexural strength were increased in P92 filler welds due to the presence of solid solution hardening elements in the P92 filler. The detrimental effect of δ-ferrite patches has been observed on the Charpy impact toughness and microhardness values of the weld fusion zone. The Charpy toughness values in the weld fusion zone were 12 ± 2, 7 ± 2, 8 ± 2 and 5 ± 3 J for P91-P91-P91, P92-P92-P92, P91-P91-P92 and P91-P92-P92 weld joints, respectively, which were lower than the minimum recommended Charpy toughness value (47 J) for ferritic steel welded joints.

Study on evaluation of through-thickness residual stresses and microstructure-mechanical property relation for dissimilar welded joint of modified 9Cr–1Mo and SS304H steel

Gas Tungsten Arc Welded dissimilar joint of modified 9Cr–1Mo (P91) and SS304H steel plate is prepared using Ni-based ERNiCrCoMo-1 super alloy filler and are post-weld heat treated (PWHT) at 760 °C for 2 h. In particular, joints are investigated for metallurgical and mechanical properties in different heat-affected zones. Furthermore, an attempt has been made to understand the following: (i) Is there any effect of mixing of Ni-based superalloy filler material on the joint? (ii) How does the PWHT process change the metallurgical and mechanical properties of joints and different sections? (iii) Does the PWHT process beneficial as compared to as-welded (AW) joint? Experimental results indicate that improper mixing of filler materials led to the formation of an unmixed zone near the weld metal and HAZ interface. The hardness, residual stress, and impact energy results confirmed the variation in mechanical properties along the weldments. The tensile strength varied from 539 MPa in as-joint to 516 MPa in PWHT, and impact energy varies from 165 J in as-joint to 40 J in PWHT condition. The maximum hardness of 375 H V is observed in P91 CGHAZ. The maximum longitudinal residual stress is estimated as 200 MPa at the top surface of the welded plate, i.e., about 2 mm depth, while the maximum magnitude of the transverse residual stresses is observed as 109 MPa at the same depth of 2 mm. In P91 HAZ, the longitudinal and transverse residual stress magnitudes are found to be in a range of 0 to ˗70 MPa. The SS304H HAZ shows the maximum value of longitudinal and transverse residual stress level at a depth of 3 mm, and it was 144 MPa and 92 MPa, respectively. The PWHT showed a drastic reduction in residual stress value in a different zone of the weldments.

Hierarchical Morphology and Formation Mechanism of Collision Surface of Al/Steel Dissimilar Lap Joints via Electromagnetic Pulse Welding

The aim of this study was to characterize detailed microstructural changes and bonding characteristics and identify the formation mechanism of collision surface of Al6061–Q355 steel dissimilar welded joints via electromagnetic pulse welding (EMPW). The collision surface was observed to consist of five zones from the center to the outside. The central non-weld zone exhibited a concave and convex morphology. The welding-affected zone mainly included melting features and porous structures, representing a porous joining. The secondary weld zone presented an obvious mechanical joining characterized by shear plateaus with stripes. The primary weld zone characterized by dimples with cavity features suggested the formation of diffusion or metallurgical bonding. The impact-affected zone denoted an invalid interfacial bonding due to discontinuous spot impact. During EMPW, the impact energy and pressure affected the changes of normal velocity and tangential velocity, and in turn, influenced the interfacial deformation behavior and bonding characteristics, including the formation of micropores which continued to grow into homogeneous or uneven porous structures via cavitation, surface tension, and depressurization, along with the effect of trapped air.

Effect of FSW process parameters on mechanical properties and microstructure of dissimilar welded joints of AA2024 and AA6082

The aluminum alloys AA2024 and AA6082 are the most common alloys used in the storage tank, pipelines, maritime frames, automobile and aerospace industries due to their high corrosion resistance and toughness.In the present work, these dissimilar aluminum alloys were successfully fabricated via friction stir welding (FSW) by varying input parameters (rotational tool speed (TRS) and welding speed). The great mixing of AA2024 and AA6082 was observed at a high rotational speed. The higher TRS enhanced the mechanical properties of the stir zone (SZ). The maximum ultimate tensile strength (UTS) of dissimilar alloys was observed 218.1 MPa at TRS of 1400 rpm with a welding speed of 30 mm/min caused by strain-free fine grains during the dynamic recrystallization (DRX) mechanism. The maximum hardness (93 HV) at SZ was observed at a TRS of 1200 rpm with a 30 mm/min welding speed. The fractured FSWed region at 1200 rpm shows the big and deep dimples, while equiaxed, fine dimples were observed at TRS of 1400 rpm.

HAZ Characterization and Mechanical Properties of QP980-DP980 Laser Welded Joints

The QP980-DP980 dissimilar steel joints were fabricated by fiber laser welding. The weld zone (WZ) was fully martensitic structure, and heat-affected zone (HAZ) contained newly-formed martensite and partially tempered martensite (TM) in both steels. The super-critical HAZ of the QP980 side had higher microhardness (~ 549.5 Hv) than that of the WZ due to the finer martensite. A softened zone was present in HAZ of QP980 and DP980, the dropped microhardness of softened zone of the QP980 and DP980 was Δ 21.8 Hv and Δ 40.9 Hv, respectively. Dislocation walls and slip bands were likely formed at the grain boundaries with the increase of strain, leading to the formation of low angle grain boundaries (LAGBs). Dislocation accumulation more easily occurred in the LAGBs than that of the HAGBs, which led to significant dislocation interaction and formation of cracks. The electron back-scattered diffraction (EBSD) results showed the fraction of LAGBs in sub-critical HAZ of DP980 side was the highest under different deformation conditions during tensile testing, resulting in the failure of joints located at the sub-critical HAZ of DP980 side. The QP980-DP980 dissimilar steel joints presented higher elongation (~ 11.21%) and ultimate tensile strength (~ 1011.53 MPa) than that of DP980-DP980 similar steel joints, because during the tensile process of the QP980-DP980 dissimilar steel joint (~ 8.2% and 991.38 MPa), the strain concentration firstly occurred on the excellent QP980 BM. Moreover, Erichsen cupping tests showed that the dissimilar welded joints had the lowest Erichsen value (~ 5.92 mm) and the peak punch force (~ 28.4 kN) due to the presence of large amount of brittle martensite in WZ and inhomogeneous deformation.

Experimental investigation on microstructure, mechanical properties, and residual stresses of dissimilar welded joint of martensitic P92 and AISI 304L austenitic stainless steel

In this study, microstructural characteristics and mechanical properties of martensitic steel P92 and AISI 304L austenitic stainless steel (ASS) dissimilar metal weld (DMW) have been examined. The welding was performed using the multipass gas tungsten arc welding (GTAW) process. The ERNiCrMo-3 (Inconel 625) filler metal was used due to its excellent compatibility with the P92 and AISI 304L ASS metals. The microstructure characterization performed with an optical microscope and scanning electron microscope revealed the presence of an unmixed zone in the form of beach, peninsula, and island at the base metal and weld fusion zone interface. Secondary phases enriched with Nb and Mo, and migrated grain boundaries (MGBs) were also observed at the weld fusion zone. The microstructural characterization at the P92 side revealed the presence of a soft ferrite zone and delta ferrite at the weld and P92 interface. The different peak temperature experienced by the P92 metal during the welding process results into the formation of three distinct zones with diverse mechanical and microstructural properties namely coarse grain heat affected zone (CGHAZ), fine grain heat affected zone (FGHAZ), and inter-critical heat affected zone (ICHAZ). The post weld heat treatment (PWHT) at 760 °C for 2 h followed by air cooling was performed to homogenize this heterogeneous microstructure formed toward the P92 side. It was observed that this PWHT does not have any significant effect on weld fusion zone and 304L SS heat affected zone (HAZ) microstructure. But, PWHT modifies the microstructure of P92 side HAZ. The tensile test, Vickers micro-hardness test, and charpy impact test were carried out to determine the mechanical properties of the DMW. The tensile strength was found as 587.709 MPa in the as-welded condition and 594.515 MPa in PWHT condition. The tensile test results indicated that specimens were failed from 304L stainless steel (SS) base metal (BM) in as-welded and PWHT condition. The charpy impact toughness test results showed that the toughness of the weld joint was very low in as-welded and PWHT condition (47J) compared to the P92 (190J) and SS 304L (285J) BM. From the microhardness examination, it was observed that the ICHAZ was the weakest zone among all the other regions due to its lower micro-hardness value compared to the other regions. After welding process, residual stresses were measured in as-welded and after PWHT condition at the center of the weld and at the HAZ of P92 and SS 304L (through the thickness of the plate) using experimental-based deep hole-drilling (DHD) strain-gauge method. The results showed that both circumferential (hoop stress) and axial (longitudinal stress) welding residual stresses were decreased after PWHT.

Experimental Characterisation and Numerical Modelling of Residual Stresses in a Nuclear Safe-End Dissimilar Metal Weld Joint

In this study, a mock-up of a nuclear safe-end dissimilar metal weld (DMW) joint (SA508-3/316L) was manufactured. The manufacturing process involved cladding and buttering of the ferritic steel tube (SA508-3). It was then subjected to a stress relief heat treatment before being girth welded together with the stainless steel tube (316L). The finished mock-up was subsequently machined to its final dimension. The weld residual stresses were thoroughly characterised using neutron diffraction and the contour method. A detailed finite element (FE) modelling exercise was also carried out for the prediction of the weld residual stresses resulting from the manufacturing processes of the DMW joint. Both the experimental and numerical results showed high levels of tensile residual stresses predominantly in the hoop direction of the weld joint in its final machined condition, tending towards the OD surface. The maximum hoop residual stress determined by the contour method was 500 MPa, which compared very well with the FE prediction of 467.7 Mpa. Along the neutron scan line at the OD subsurface across the weld joint, both the contour method and the FE modelling gave maximum hoop residual stress near the weld fusion line on the 316L side at 388.2 and 453.2 Mpa respectively, whereas the neutron diffraction measured a similar value of 480.6 Mpa in the buttering zone near the SA508-3 side. The results of this research thus demonstrated the reasonable consistency of the three techniques employed in revealing the level and distribution of the residual stresses in the DMW joint for nuclear applications.

Influence of Rotary Friction Welding Parameters on Tensile Strength and Length of TMAZ of Dissimilar Welded Joints from 32G2 and 40KhN Steels

In this work, pipe billets with a diameter of 73 mm and a wall thickness of 9 mm from steels 32G2 and 40KhN are friction welded with an aim to optimize the process parameters. The friction pressure, the forging pressure and the length of the fusion varied. After the implementation of various welding modes, tensile tests and metallographic studies were carried out. The optimal welding parameters have been established, which make it possible to obtain tensile strength at the level of the 32G2 base metal. The study results of the microstructure and SEM fractographs after the optimal welding mode are presented.

Evaluation of bond interface characteristics of rotary friction welded carbon steel to low alloy steel pipe joints

In the present investigation, rotary friction weld joints were prepared between carbon steel and low alloy steel pipes. These types of similar and dissimilar configurations are in general, used for drill pipe joining. Low alloy steel for the friction welding in dissimilar configurations were used in two different microstructure state; a) as-received and b) quenched and tempered. The friction weld joints showed three distinct weld microstructure characteristics; a) radial plastic flow, b) axial plastic flow and, c) partial heat affected zone, for joining configurations. In general, microstructure characterization revealed grain size refinement and carbide precipitation in the vicinity of bond interface for all types of similar and dissimilar steel joining conditions. A characteristic bond layer width of ~2 μm was developed between the dissimilar steel weld joints whereas it was found to be absent for the similar weld joints. These weld joints were evaluated for their mechanical properties by using conventional tensile tests and furthermore by automated ball indentation technique. The study has also shown that in the case of dissimilar steel joints the mechanical properties of the bond interface can be obtained aptly by using an automated ball indentation technique. The quench and temper treatment given to the low alloy steel resulted in the improved bond interface strength. The improvement of the mechanical properties of the weld joints was attributed to the synergistic effect of grain size refinement and tempered martensite microstructure.

Residual stress and simulation of 304–430 stainless steel dissimilar laser-welded joints incorporating materials heterogeneity

AbstractAn Nd:YAG laser device is used to conduct laser welding for a 1 mm austenitic stainless steel plate and a ferritic stainless steel plate. A finite element model of the shear punching test is constructed to generate the maximum shear strength in the weld, and the finite element model of laser welding is created using the welding temperature field. The hole drilling test result and the residual stress generated by two algorithms (Nonuniform-material and uniform-material) are compared. Results show that a drop-off of residual stress in the central area of the welded joint is observed when materials heterogeneity is disregarded. When materials heterogeneity is considered, the residual stress curve indicates smooth transition. The value of the latter appears reasonably similar to the experimental value. Therefore, this solution is advantageous in terms of residual stress simulation in dissimilar welded joints and does not critically affect residual deformation.

Environmentally assisted cracking in the fusion boundary region of a SA508-Alloy 52M dissimilar weld joint in simulated primary pressurized water reactor environments

Environmentally assisted cracking behavior in both parallel and perpendicular directions to the fusion boundary (FB) of SA508-Alloy 52M weld joint were investigated. The grain boundaries of dilution zone adjacent to the FB are more prone to cracking than the FB. Strength mismatch and galvanic corrosion promote crack initiation along the FB or the partially mixed zone/low alloy steel interface with the loading direction vertical to the FB. In addition, the FB hinders crack growth perpendicular to the FB, most likely because severe pitting decreases the crack tip stress/strain and oxidation along the FB increases the crack growth distance.

Evaluation of Weld Joint Strength Reduction Factor due to Creep in Alloy 740H to P92 Dissimilar Metal Weld Joint

Evaluation of Weld Joint Strength Reduction Factor due to Creep in Alloy 740H to P92 Dissimilar Metal Weld Joint

The effect of pulse current changes in PCGTAW on microstructural evolution, drastic improvement in mechanical properties, and fracture mode of dissimilar welded joint of AISI 316L-AISI 310S stainless steels

In this paper, the effect of pulse current changes in the Pulsed Current Gas Tungsten Arc Welding (PCGTAW) on the various properties of dissimilar welding of AISI 316L-AISI 310S stainless steels was investigated. 10 mm thickness steel sheets were joined by the PCGTAW process with the background current (Ib) of 55, 70 and 85A, as well as the peak current (Ip) of 110, 130 and 150A. Then, optical microscopy (OM) and Field Emission Scanning Electron Microscopy (FE-SEM) techniques were used to study the microstructural evolution in different areas of the welded joints. Also, tensile, Charpy impact and Vickers microhardness tests were used to evaluate the effect of the pulsed current changes on mechanical properties. Finally, the fracture surfaces of Charpy impact and tensile tests samples were studied by FE-SEM. The weld metal (WM) microstructure consisted of austenite dendrites together with a low amount of delta ferrite in the grain-boundaries. Results also showed that by increasing Ib and decreasing Ip, the microstructure of the WM was changed from columnar dendritic to coaxial, and a very fine, dendritic one. This condition led to the reduction of the size of the dendrites and the amount of delta ferrite ingrain boundaries of the WM, as well as a reduction in the width of Unmixed Zone (UMZ) area. Moreover, all the welded joints were fractured from the AISI 316L stainless steels side. However, the results of the Charpy impact and microhardness tests showed that with the above variation in the welding parameters, hardness value and fracture energy of the WM increased significantly. Fractography of the surfaces showed a completely ductile fracture for both tensile and Charpy impact tests samples.

Decisive impact of Filler-free joining processes on the Microstructural evolution, tensile and impact properties of 9Cr-1Mo-V-Nb to 316 L(N) dissimilar joints

Filler-free (FF) welding processes namely, Activated Tungsten Inert Gas welding (ATIG), Laser Beam Welding (LBW), and Friction Stir Welding (FSW) were utilized for joining the nuclear grade 9Cr-1Mo-V-Nb ferritic-martensitic steel and 316 L(N) austenitic stainless steel. A comparative investigation was made by assessing the weld geometries, metallurgical features, material mixing proportions, carbon diffusion behaviour, and mechanical properties of the post-weld heat-treated (PWHT) dissimilar weld joints. Geometries of the weld zones were observed with the transverse and longitudinal macrographs. Metallurgical features were examined by optical microscopy (OM) and Scanning electron microscopy (SEM). Three-phase microstructures were identified in the dissimilar weld zones (DWZ). The elemental distributions were identified by Energy-dispersive X-ray spectroscopy (EDAX). The mixing proportions of the dissimilar alloys and the formation of δ-ferrite in the dissimilar heat-affected zones (HAZ) and DWZ were analytically quantified. Moreover, the diffusion activity of carbides/interstitial carbon atoms was examined by Secondary ion mass spectroscopy (SIMS). In the FSW joints, the intermingled microstructures are recorded with high and stabilized hardness values as compared to the DWZ of the ATIG and LBW joints. In the transverse tensile test, all FF joints were failed at the 316 L(N) base metal (BM) region. Tensile and impact testing of all weld metal indicated that, the weld metal region of the LBW joint exhibited higher strength and lower toughness as compared to the ATIG and FSW joints. The presence of untransformed, recrystallized fine equiaxed austenite along and refined martensitic structure arranged in an alternate layers within the weld metal region of FSW joint caused the higher toughness property than the ATIG and LBW joints.