Cutting Thick Steel Plate

Posted by on Aug 22, 2017 in Manufacturing | 4 comments

New improvements, including the utilization of fibre consumption and high-temperature oxygen, assist gas, create the Nd: YAG laser an option for cutting thick mild steel plate

After a report in ICALEO , it’s currently feasible to acquire high quality cutting of mild steel plate into 50 millimeter thickness with a fiber-delivered Nd:YAG laser in event powers as low as 500 W. This is carried out by employing the Lasix procedure, reported in Industrial Laser Solutions, also by harnessing the substance removal capacities of high-pressure oxygen assist gas.

The benefits of utilizing this procedure using a fiber-delivered Nd:YAG laser in contrast to utilizing the CO2 laser will be the much better positional stability of the laser area, the greater divergent laser beam and greater absorptivity of the Nd: YAG beam from the workpiece, which enables a greater use of the beam in lower forces. This technology is ideal for laser job shops that can’t justify purchasing a higher-power laser, however, wish to improve the depth of mild steel plate which may be cut. Additionally, the technologies would also help them decrease subcontracting of thick-plate function to plasma screen, oxyfuel or water jet cutting job shops.

In a nutshell, the technology raises the ability of a present Nd: YAG laser without any significant changes necessary to the laser optics and gasoline delivery system and with no substantial capital outlay. Using an optical fibre to provide the laser beam opens new chances for the in-situ robotic cutting edge of thick-section 3D structures.

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In every case that the laser beam is extremely divergent with the place incident on the workpiece surface bigger in diameter than that of those co-axial help oxygen jet.

This kind of cutting utilizes the laser since the initiator of the leading procedure (that the laser preheats the surface to approximately 900° C), and this is predominantly fueled from the exothermic reaction of the steel using all the oxygen assist gas. As a result, the constraint of the oxygen assist gas dominates the high quality and character of this cut and kerf form. This approach has enabled the use of a comparatively low-power (~0.5 – 2.0 kW). Fibre-Delivered Nd: YAG laser to reduce mild steel plate between 20 and 32 millimetres in thickness using LoPOx and between 32 and 50-millimetre thickness to HiPOx.

The compiled cut rate results for both thick plate procedures along with standard cutting of thinner mild steel plate using the Nd: YAG laser. This shows that despite the publication approach to cutting edge with LoPOx and HiPOx the trimming mechanism is comparable.

The high-quality cut surface which may be gotten by utilizing LoPOx cutting in addition to the event laser powers and also cut rates for 20mm-thick light steel plate with a 3.5millimeter diameter co-axial nozzle. Here, the important problem is laser power level in the initiation of this cut, with initial signs of inadequate laser electricity being the inadequate quality of the resultant surface at the start of the cut, which improves because the heat generated inside the kerf conducts towards the upper surface of the workpiece. Kerf widths are usually 2.5 to 3.5 mm using a taper of 2 to seven levels. See more..

A profile surface and cut finish for 40mm-thick, 250-grade light steel plates cut at 150 mm/min. Employing HiPOx. The surface is quite smooth in contrast to the traditional cutting edge, with very little if any oxide and a vertical top border. Employing HiPOx cutting there’s big clearance (two – 4.5 mm) involving the co-axial nozzle and workpiece, raising nozzle lifetimes and lowering the potential for injury and collision.

A significant facet of profile trimming is piercing. Piercing of stainless steel plate utilizing HiPOx is quite fast, using the 32mm thickness excavated in under one minute–compared to the normal 12 seconds required to get an oxyfuel system. This raises the chance of laser profile cutting inner shapes inside a thick plate. Figure 4 displays the piercing of 32mm thick, tier 250 light steel plate together with the consequent pierced hole found in the cross section. During piercing there’s a substantial quantity of dross ejected up that could afterwards inhibit the cutting procedure by sitting along with this plate. Therefore, novel methods have to make certain that the upper surface of the workpiece is retained clean after piercing and that the co-axial nozzle itself can also be kept clean.

The stream of high energy oxygen gas inside the kerf creates small shock attributes, which can be observed when watching the melt flow. These leave little marks on the otherwise smooth cut surface nonetheless, they may be readily controlled and reduced by calculating of the cutting parameters.

Research activities are currently directed at finding out the best laser cutting requirements for a selection of mild steel depth, enhancing the cutting head layout and substance piercing. This job in laser cutting a part of IRIS’s approach to creating new procedures and industrial uses for lasers.

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