Steel Cutting

Metal laser cutting

admin — Wed, 14 Sep 2011 12:47:34 +0000

The metal laser cutting finds very wide application range in many industries where metal elements are required. Construction, automotive, machinery industries, medical equipment, artistic creations that’s only a few of areas where the unity of precision and power is necessary to achieve the goal. Uncertainty and not exact results of produced parts in yet used steel cutting methods is the main reason for looking around to find a better ways of cutting. Not accurate production affects not only time and effort to get final and best fitting parts of the machines or constructions, but also consumes the budget and creates more complaints from the recipients of service or product customers. Laser steel cutting allows for flexible production stratedy starting from short product lines to big industrial scale projects. It can be very efficient in designing and testing phase with easy and precise adjuting any detail parameters. Precision laser cutting with ready-to-use products, without necessity for any further polishing of produced parts, removes another place to let the errors get into. Metal laser cutting reduces unpredictability factor also with the full automation of the process and the computer analysis software reduces efficiency of used steel. The current laser cutting technology encorages the engeneers to create even more sophisticated and serviceable projects and discover fresh ways for steel application in brand new products.

Waterjet steel cutting speed comparison

admin — Mon, 04 Jul 2011 12:54:18 +0000

Waterjet steel cutting speed comparison of KMT Waterjet New Streamline PRO machine working in different pressure modes. Pressure range varies between 4.100 bar to 6.900 bar on four screens in parallelly on the screen.

Waterjet cutting

admin — Thu, 30 Jun 2011 13:24:15 +0000

If you ever wondered how it is possible to cut such hard materials like stone or steel with usage of water we will cast some light on that topic. Cutting steel with water doesn’t belong to the cheapest options available on the steel cutting market services but it has some unprecedented and unique advantages over all the other methods of steel cutting. The thing we start with is the quality. Yes, quality is the king in steel cutting. Without ability to cut with scalable quality levels of edge smoothness we limit the technology practical use. Fortunately we can scale the quality in water cutting by 5 general factor, where factor 5 is the highest and smoothest one which doesn’t need to be corrected afterwards.
With water steel cutting mechanical pressure around the cutting area is very limited which is great but the most spectacular point of cutting steel by water is no heat influence, no burning or melting down. Waterjet cutting is done in about 100 °F degrees which doesn’t impact steel structure in area of cutting in any way so it lefts the cutted steel edge free of deformation and high-temperature degradation of steel. It is also very clean, we can say almost every part of technological processing is free of chemicals emmission or other pollutions.
Water used to cutting is clean, fueled by electric power and for abbrasive waterjet cutting there can be utilized pure sand (garnet).
With waterjet cutting we can cut various types of steel: stainless steel, aluminium, copper and different alloys.

Plasma cutting video

admin — Mon, 06 Jun 2011 11:15:55 +0000

On the short video clip below we can see the model of machine cutting steel with plasma technology. Brief description gives general view of the technology uses plasma stream:

Steel cutting market preferences

admin — Tue, 31 May 2011 13:32:46 +0000

The most popular methods of cutting steel today utilize oxygen, plasma, laser and water. The first two methods contains almost ninety percent of world sales of machines dedicated for cutting steel. Standard oxy-fueled cutting burners are quite efficient and are able to cut to steel objects up to 300 mm thick. With special industry oxy-gas burners steel can be cutted even up to 2000 mm. On the weaker side of oxygene fueled burners lies quality of edge of final steel details and significant deformations. It cannot be applied also if we predict neccesity of cutting stainless steel, aluminium or copper. And this is big moment when plasma and laser cutters come into the scene. Growing demand on quality products is putting the cutting steel machines market into that direction. So, let’s make some briefly summary of main decision points when we choose right cutting technology for our factory:

what kind of steel we need to cut
quality of edge along cut path, distortion, chemical pollution of the edges and geometry of edges.
cutting line lenght and the complexity degree of shapes of the products
production approach: manual operator, mechanical or automated process
maintanace cost: availability and price of service, price of spare parts and it’s durability.

Steel Cutting

admin — Tue, 24 May 2011 11:05:29 +0000

Cutting steel is the process of dividing single material sheet thorough its whole thickness. In usual cases desired cutting angle is simply orthogonal to the surface. Within the steel cutting technology main purposes to achieve are: narrow cutting slit, minimize consumption of energy, maximizing the quality of cut edges and limit heat influence over heating area as possible.

We can forge and split steel sheets by using different methods. All of them have their own advantages which makes every of them usable in various situations. It starts from simple, hand operated oxy burners to the highly automated plasma and laser cutting cnc machines which. With mobile oxy burner we can access to places which are not flat or simply shaped or difficult to access with heavy and big machines. CNC steel cutting machines are usually dedicated to precision print into the flat sheet projects prepared before on specialised software. Similarly to ink, laser printers or plotters which make possible for computer drawings to appear on paper, cnc steel cutting machines allow to create very complex details appear real in steel.
Ideal cutting process would allow to separate steel structure on atomic (covalent) bonds alongside given patch without any influence on physical features of cutted material. Steel cutting technology today doesn’t give perfect solution to those conditions and the huge step will be made when nanotechnology come into a game for real.

But also today we can achieve very well results (and usually good enough for most uses) in precision steel cutting by using modern and properly maintained machines or by combining various methods alltogether. As it is not a surprise, well maintanance and servicing is crucial in getting expected results.

Cutting Steel with Laser

admin — Fri, 08 Apr 2011 11:45:35 +0000

General idea of laser steel cutting works by forced amplification of light emmision. Laser machining operates by highly concentrated and amplified light beam. Condensation of power is between 10^8 and 10^14 W/m2 on surface. Next, the enegry of photons within a laser beam is converted into very hot heat which burns or melts down and evaporates machined material (steel sheets for example). Laser machining usually utilises gas lasers (carbon dioxide lasers CO2). With laser cutting we can distinguish some special features like: cutting without direct contact of header with cutted surface; no horizontal force is needed to move through cutted material (but we need precise speed regulation to archieve proper results instead); high speed of laser cutting process with narrow area affected by generated heat (reduced tension and deformations); high precision with level around 10^-3 mm order of magnitude; quiet and smooth running process; full automation; not loosing cutting parameters caused by hardware wearing mechanical contact with steel.
Energy of the laser beam is deployed to cut flat steel blocks and steel sheets placed in 3D space using holders, for drilling holes in hard materials with high accuracy and precision, welding or melting materials and many more practical usages. Cutting flat steel shets by numerically controlled laser machines (CNC) gives quick cutting speed with repeatable and high quality features of manufactured products.

Steel rougness

admin — Wed, 09 Mar 2011 12:35:26 +0000

Surface roughness (or just roughness) (Ra unit) is a feature of solid (object, steel) surface. It is measured by optical or mechanical examination of flatness divergence which don’t reflect it geometrical shape. Rougness measure count on about scale at least one order of magnitude smaller than standard measure unit. We differentiate rougness from waviness of steel sheet surface which is can be an outcome of machine construction, vibration caused by circular parts or so. Rougness mainly depends of kind of steel and machining method. We describe it with Ra symbol followed by a destined value. For example Ra 2,25 is equal to abrasive flow machining. The change in surface roughness decreases with the increase in cross section of the work-piece and also increases with the increase in length of the work-piece. Quality polishing can give Ra value even with 0,01 precision.

Plasma cutting gases

admin — Thu, 24 Feb 2011 15:31:16 +0000

Plasma cutting can be lead by a hand controller and an automated one based on electronic and mechanical interfaces on every stage of the technological process. Classic manual welding thanks to small weight of arc and currency invertors can be applied in joining parts of complex design constructions where they are difficult to access in any other way. With plasma technology new possibilities are opening like underwater cutting on high depths, even in salty water of sea by specialized robot units. Such extremal conditions requires replacing of the nozzles and cathodes in the head of cutter more frequently. Cutting steel technology significantly depends of jet qualities and strictly following after producers specifications is must to archeive a desirable outcome. For plasma cutting we use dedicated burners with working current between 30-40A and 100-1200A for high powered cutting.
Plasma burners dedicated for manual cutting are cooled widely by air.It very efficient for cutting with lower parameters of power, when plasma arc currency is below one hundred amperes. High power burners demands more effective water cooling and cnc automation. Improved models of burners are based on selfcalibrating jets and electrodes to preserve strenght and durability as long possible. Matching and adjusting particular bulding blocks of plasma burners we can result in numerous cutting parameters to allow for significant cost reduction without compromise on cutting speed. Plasma gas melts and flushes down liquid steel from a slot while a shelding gas protects the area of cutting from air (and gives an extra colling to it). Application of additional narrowness of plasma arc by shelding gas increases thickness to plasma stream and it’s heat which is is a good way to increase speed of cutting with the same working currency. In this case we ususually use an argon or mixture of it’s mixture with hydrogen or nitrogen. Kind of steel which is cutted down determines kind of a second shelding and narrowing gas then. For lowcarbonised steel we can apply air or oxygene which gives even more speed up for cutting steel by it’s exothermic combustion of steel feature. Because of prices of gases based on argon and hydrogens the industry makes big efforts to apply new and cheaper gas solutions which gives same quality results.

Plasma cnc cutter in garage

admin — Mon, 13 Dec 2010 09:57:56 +0000

How do you think, does plasma cnc cutter fit into your garage? Check this out and also how nice shape you can form with this tool. Without a haste, even without huge jet power you can obtain great results. This is like a professional technology comes under our roofs, to our homes – just watch a moment:

Efficient plasma cutting

admin — Sat, 11 Dec 2010 16:15:15 +0000

For the begining we present some of main basic plasma cutting parameters which descriptions and reciprocal dependencies will be explained below:

electric current [A]
arch currency [V]
speed of cutting [mpm}
pressure of gas [MPa] and the flow pressure [lpm]
construction of an Electrode
radius of jet nozzle
position of gas burner relative to cutted sheet of steel

On case of plasma cutting operated by hand the worker decides only about a speed of cutting and the jet distance to the cutted object. Remaining parameters are constant and maintained by driver unit working on preconfigured settings. Electric currency is the key factor which decides about temperature and power of resultant plasma arch. When we inceare electric currency we can achieve faster cutting velocity and we are able to cut thicker steel sheets, but the stability of electrodes lasts shorter. To strong electric currency results in worse quality of cutting and widening of the slit. On the sides can also appear some round edges and warped perpendicularity. If the currency is to weak cutting can fail or give some unnecessary metal sludge in lower parts.
Another parameter which is vital for steel cutting process is a voltage of electric arch and it requires to be provided precisely by computer numerical control (CNC). Because of highly condensed plasma in the arch it voltage have to equal values close to 50 ÷ 200 V. The source of an electric currency needs to give an output about 150 ÷ 400 V on the idle gear. Thanks to high heat energy or plasma arch we can achieve wide range of cutting speeds. The speed of cutting inevitably decides about quality of final workmanship especially in manual operating mode. Obviously, for this kind of relations like speed on the one hand and the quality on the other they correlate in inverse proportionality (but not linear).
To quick movement of cutting header the power of beam is to weak to properly affect cutted area. The space between divided parts decreases till the moment when plasma doesn’t make it’s way through steel sheet and leaving melted steel layer on the bottom which is perplexingly difficult to polish or to get rid off. In consequence when plasma cutting velocity is to low, plasma beam operates to long in one point, burned hole and aperture on both sides of cutted edge becames wider. The edge also diverges from the orthogonal angle of beam, upper side of metal round-offs and the down side sometimes cover with melted steel debris. Plasma jet velocity exhaust from header and it’s temperature comes from combination of following: electric currency, the shape of propelling nozzle, it’s diameter, distance from cutted surface, gas used for creating plasma and the pressure of that gas. The kind of gas has to be matched up with kind of cutted material to get optimal results. Most widely used gases are oxygen, nitrogen, air, argon and combinations of hydrogen with argon or nitrogen. Because of high price of argon, which served for first plasma cutters the technology developers aimed to incorporate different (and cheaper) gasses to make cutting steel by plasma more efficient and affordable.

Todays plasma technologies allow to attain requirements for best quality products and high speed of steel machining. It also saves energy costs. In future we predict that plasma cutting steel technology still will be in good shape in comparison for it’s main competitor like laser steel cutting technology.

Steel Cutting by Fiber Laser

admin — Thu, 02 Dec 2010 11:54:35 +0000

Let’s take a quick glance on a high power fiber laser during work (not gas lasers). Complex and smooth shapes like this fancy butterfly are cutted in 2mm stainless steel like picture printet od sheet of paper. Extreme precision conjuncts here with fast velocity of cutting and decides on quality of final product and new designs possibilities.

Movie features: Brahmastra Laser Cutting System.

Some of the main features of fiber based laser cutters:

Perfect Beam Parameter Product (BPP)
Constant BPP Over Entire Power Range
Estimated Diode Lifetime over 100000 hours
Small Focus Over Large Working Distance
Over 25% Wall-Plug Efficiency
Very Compang and Easy to install
Integrated Coupler or Beam Switch
Modular “Plug&Play” Design
Maintenance Free Operation