- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
A review on the laser welding of coated 22MnB5 press-hardened steel and its impact on the production of tailor-welded blanks
摘要： The current demand for vehicles with high fuel efficiency, improved safety and enhanced crash-worthiness qualities is being met by making use of high strength components with tailored mechanical properties which are made using tailor-welded blanks. During their production, the surface of the blank needs to be protected against oxidation and decarburisation. Protective coatings are used to protect the steel surface, with Aluminium-Silicon or Zinc-based coatings being the most popular. This work provides a review on the state-of-the-art as well as the issues associated with the laser welding of coated 22MnB5 grade steel to be used in the production of tailor-welded blanks. The paper provides a summary of existing solutions available to overcome these issues while discussing their limitations and the potential for future work.
关键词： Fibre laser welding,tailor-welded blanks,22MnB5,Zn-Coating,press-hardened steel,ultra-high strength steel,Al–Si coating,hotstamped parts
更新于2025-09-23 15:21:01
-
The protective capability of the laser welded armour steel plates
摘要： Despite the intensive development of plastics and composite materials in the case of armours employed to protect vehicles, armour steel remains a material commonly and effectively used. This is especially evident in the base armour of armoured vehicles, where the body is made of welded armour steel plates. However, the area of joining both the weld and the heat affected zone are sensitive areas with the reduced protective capability. In the case of laser welding in comparison with methods such as shielded metal arc welding and gas metal arc welding, it is possible to narrow down the above mentioned areas. The paper presents the results of research on the protective capability of welded zone of armour steel plates with a hardness of 500 HB. In the first part of the work, in order to select the proper parameters for the bonding process, different connection variants were made and their microstructure and selected mechanical properties were analysed. After selecting the best variant of the welding process, samples (200 mm (cid:2) 200 mm) consisting of two welded plates with dimensions 100 mm (cid:2) 200 mm were made for testing. The thickness of the plates was selected in such a way that in the areas outside the bonding zone, the lack of complete perforation by the projectiles used in the tests is guaranteed. The samples were shot at the weld location and at different distances from the weld to verify, for the chosen method of joining steel plates, if the welded armour loses its protective capability and, possibly, how wide this area may be.
关键词： ballistic tests,Armour steel,laser welding,quenched and tempered steel
更新于2025-09-23 15:21:01
-
Laser-arc hybrid welding of 12- and 15-mm thick structural steel
摘要： High-power lasers are very effective in welding of plates thicker than 10 mm due to the keyhole mode. High-power intensity generates a vapor-filled cavity which provides substantial penetration depth. Due to the narrow and deep weld geometry, there is susceptibility to high hardness and weld defects. Imperfections occur due to keyhole instability. A 16-kW disk laser was used for single-pass welding of 12- to 15-mm thick plates in a butt joint configuration. Root humping was the main imperfection and persisted within a wide range of process parameters. Added arc source to the laser beam process may cause increased root humping and sagging due to accelerated melt flow. Humping was mitigated by balancing certain arc and other process parameters. It was also found that lower welding speeds (< 1.2 m/min) combined with lower laser beam power (< 13 kW) can be more positive for suppression of humping. Machined edges provided more consistent root quality and integrity compared with plasma cut welded specimens. Higher heat input (> 0.80 kJ/mm) welds provided hardness level below 325 HV. The welded joints had good Charpy toughness at ? 50 °C (> 50 J) and high tensile strength.
关键词： Mechanical properties,Toughness,Thick steel,Hybrid welding,High strength steel,Laser welding
更新于2025-09-23 15:21:01
-
Influence of laser weld shape on mechanical and fatigue behaviour of single lap laser welded joints
摘要： Traditional manufacturing processes, like arc welding and resistance spot welding, are still the main welding processes to join structural components used across the on/o?-road vehicle industry. Due to the abundance of data, experiences and insights over the decades of usage, lot of fatigue design data has been generated for different joint geometries produced using these methods. The laser welding process has excellent capabilities to join thin sheet metal structures with minimum heat input resulting into lower deformation and improved productivity that offers significant benefit as compared to the arc and resistance welding processes. However, due to the agility of designing joint configurations and limited availability of understanding regarding the fatigue behaviour of laser welded joints, the need arises for the fatigue design data. Most of the research presents the use of straight linear shape laser welds and limited knowledge exist regarding the influence of shape of laser welds on mechanical and fatigue performance of the laser welded joints. The laser welded joints produce small notch like radius at the root of laser weld which could act as a stress raiser causing early crack initiation. For this work, C-shape laser weld has been selected as the geometric shape in comparison to the straight linear shape of laser weld produced on a series of single lap joints. Detailed fatigue experimental investigation has been carried out for linear and C-shape laser welded joints tested in 3 different orientations with respect to the applied cyclic load and several different R-ratio’s and the results are compared. The metallurgical studies have been carried out to understand the failure mode and micro-hardness variations across the weld and heat affected zone. Further, the residual stress profiles have been compared for the C-shape laser weld with the linear welds using detailed X - Ray Diffraction based residual stress measurement.
关键词： Laser Weld,Ultra-high strength steel,C Shape,Crack propagation,High strength low alloy steel,Crack initiation
更新于2025-09-23 15:21:01
-
Dynamic Laser Absorptance Measured in a Geometrically Characterized Stainless-Steel Powder Layer
摘要： The relationship between real powder distributions and optical coupling is a critical building block for developing a deeper physical understanding of laser-additive manufacturing and for creating more reliable and accurate models for predictable manufacturing. Laser-light absorption by a metal powder is distinctly different from that of a solid material, as it is impacted by additional parameters, such as particle size, shape distribution, and packing. Here, we use x-ray computed tomography to experimentally determine these parameters in a thinly spread austenitic stainless-steel powder on a metal substrate, and we combine these results with optical absorptance measurements during a 1 ms stationary laser-light exposure to simulate the additive-manufacturing process. Within the thinly spread powder layer, the particle volume fraction changes continuously from near zero at the powder surface to a peak value of 0.72 at a depth of 235 μm, with the most rapid increase taking place in the first 100 μm. The relationship between this particle volume fraction gradient and optical absorptance is investigated using an analytical model, which shows that depth-averaged absorptance measurements can measure the predicted average value, but will fail to capture local effects that result from a changing powder density. The time-averaged absorptance remains at levels between 0.67 and 0.80 across a two orders of magnitude range in laser power, which is significantly higher than that observed in solid stainless-steel experiments. The dynamic behavior of the absorptance, however, reveals physical phenomena, including oxidation, melting, and vapor cavity (keyhole) formation, as well as quantifying the effect of these on the absorbed energy.
关键词： keyhole formation,laser-additive manufacturing,stainless-steel powder,x-ray computed tomography,optical coupling,optical absorptance,particle volume fraction
更新于2025-09-23 15:21:01
-
Measurement of Weld Zone Properties of Laser-Welded Tailor-Welded Blanks and Its Application to Deep Drawing
摘要： Weld zones in tailor welded blanks have different mechanical properties than the base metals and thus have significant effects on formability. In this work, flow stresses of weld zones in laser-welded dissimilar dual-phase steels were measured. Strains at the weld zones of notched specimens were measured using the digital image correlation method and the flow stress data were corrected considering the anisotropy. For validation, finite element simulations were performed for the cup drawing process by considering the measured weld zone properties, and the weld line movements were compared with the measurements.
关键词： Laser welding,Formability,Digital image correlation,Dual-phase steel,Flow stress
更新于2025-09-23 15:21:01
-
Reinforcement of a laser-textured 316L steel with CuCoBe-diamond composites through laser sintering
摘要： The aim of this work was the production and the characterization of a laser textured 316L stainless steel reinforced with CuCoBe-diamond composites by laser sintering. The composites were obtained from CuCoBe and synthetic diamond with different particle sizes by mechanical alloying. The influence of the reinforcement on the physical, chemical and surface properties was analyzed. The results showed that the textured pattern consisted of square pyramids with a machined area of approximately 80%. The interfaces between the steel and the reinforcement after sintering are well defined and sharp. A good adherence of the diamond particles to the CuCoBe matrix was achieved. The laser sintering process did not induce any phase transformations or oxidation of the reinforcement. The steel reinforced with the biggest diamond particles exhibited substantially better surface performance than the untextured material.
关键词： composites,sintering,diamond,steel,Mechanical,316L,CuCoBe,alloying,texturing,laser
更新于2025-09-23 15:21:01
-
In situ monitoring of the layer height in laser powder bed fusion
摘要： In situ process monitoring has frequently been cited as an critical requirement in certifying the performance of laser powder bed fusion (LPBF) components for use in high integrity applications. Despite much development in addressing this need, little attention has been been paid to monitoring the layer thickness during the process. In this paper, a laser displacement sensor has been integrated into the build chamber of an LPBF machine, and the height of the top surface layer of a component has been monitored during a build. This has permitted the deposited layer thickness to be measured throughout the build, and the effect on this of a change in processing conditions is characterised. The thermal contraction of the top layer in between successive laser scans has also been evaluated. This demonstrates the potential of utilising laser displacement sensory as a process monitoring tool in LPBF and provides insightful data for implementation in detailed process models.
关键词： 316L steel,in situ testing,selective laser melting
更新于2025-09-23 15:21:01
-
Study on ?′-ferrite evolution and properties of laser fusion zone during post-weld heat treatment on Al-Si coated press-hardened steel
摘要： Laser welding of Al-Si coated press-hardened steel (PHS) was still a challenging due to the formation of ?-ferrite in the fusion zone. However, it was ambiguous on the ?-ferrite evolution during post-weld heat treatment (PWHT). In this study, Al-Si coated PHS was welded by laser ?ber and then heat-treated at various temperatures (650 ?C, 950 ?C and 1050 ?C), and the microstructure evolution was investigated by in situ-observation. Mechanical properties and formability of welded joints was analyzed. The results showed that ?-ferrite did not go through phase transformation during PWHT regardless of any temperature, but with a grain boundary ?atted and movement. The presence of coarse ?-ferrite after PWHT was the responsible for the decreasing of tensile strength and formability of welded joints. The initiation crack was easy to generate in the phase interface between ?-ferrite and martensite to form a local brittle fracture zone ?nally. This study results provides a new theoretical criterion for the properties improvement on the laser welding of PHS without removing Al-Si coating.
关键词： Laser welding,Post-weld heat treatment,Al-Si coating,Press hardened steel ?-ferrite
更新于2025-09-23 15:21:01
-
Optimisation of edge quality on stainless steel 316L using low power fibre laser beam machining
摘要： In the manufacturing industry critical importance lies upon the dimensional accuracy of a machining part especially for precision assembly operation in sheet metal cutting. But the converging diverging shape of the laser beam profile causes the existence of kerf taper in laser cut specimen. Use of low power fibre laser beam machining in the order of 50 watt makes it extremely difficult to perform good quality cut on stainless steel sheet metal. Cutting wedge angle, a relatively uncommon process variable performs a critical role for the determination of unevenness in kerf characteristic. Cutting result of kerf taper with a 50-watt fibre laser is presented in this investigation. The purpose of the investigation is to reveal the ability of the low power fibre laser to cut stainless steel AISI 316 L with 1 mm thickness. The effect of the cutting wedge angle and other process variables like power, duty cycle, pulse frequency and scanning speed has been analysed through an application of Response Surface Methodology (RSM) with CCD technique. Validation of experiments on the proposed model reveals that adjustment of proper process parameters can optimise the required edge quality.
关键词： Laser cutting,response surface methodology,kerf taper,cutting wedge angle,AISI 316 L stainless steel
更新于2025-09-23 15:21:01