Steel Cutting » steel cutting

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.

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.

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

Plasma cutting edge and oxidization

admin — Fri, 10 Sep 2010 12:38:16 +0000

As a source of the direct currency, which is negative polarised in plasma cutting, are in use teristory rectifiers and inverters which allows to fluent operating on electric currency, high efficiency and reasonable size. Variability of currency is needed for different thickness of cutted sheet. The whole process of cutting is usually fully robotised. In the industry scale of production the quality and speed of cutting can be easely balanced and the results can be repeated with high precision. Of course there are also ways to make the proces of plasma cutting more custimzed with direct manual operating, semi-manual with the CNC methods on the other end. Because of high emission of hazardous fumes, there is always necessity for room ventilation.

Oxidization and edge dirtness are not a marketable effect. This quality level depends of type of gas used and kind of steel cutted. For usual stainless steel it is enough to polish 0.5 milimeter deep to remove all the area affected with the heat from the surface. Settling the process of cutting under the water allows to significant oxidization decrease and speeds up the cutting itself. If we compare classic, mechanic way for steel cutting by saw to plasma cutting, we loose less material if we use axe. More, the angle of cutted edge needs to be allowed for further processing to develop a perfect one. If we don’t take it within process of polishing overheated area, we need to add another steep into all production way.

Thermal cutting

admin — Thu, 08 Jul 2010 10:51:25 +0000

The main method for thermal cutting is a cutting with Oxy-fuel torch. That process is utilised to cut stainless steel not necessairy of the top quality, because during the process occurs oxidization along with high heat emission in cutting area. That’s why that kind of cutting is applied only when the other’s are not available for some reasons. While cutting with plasma, the steel is melted down only in limited area with very high temperature (20000 – 35000 °F) in the result of very condensed plasma stream. By plasma, we mean highly ionized and strongly concentrated gas which builds plasma streamed inbetween electric-arch created among electrodes. Commonly used plasmogen is air.

As mentioned before, the plasma cutting process is based on melting down the steel and throwing out it debris with high density electric arch of plasma, which burns between infusibility electrodes and cutted object. Infusible electrode is made of copper with zirconium plate (or hafnium) and needs very intense colling down by air or water. The temperature of plasma stream depends of electric currency, arch narrowness degree and also a kind and ingredients of plasmatic gas.
For steel cutting are used only gas burners with iron arch. The spark on arch is obtained by high voltage electric impulse or by high frequency current. This makes possible to cut every conducting material (cast iron, steel, cuprum, aluminium etc.). Nonmetalic materials can be cutted only with plasma torches based on independent arch.

will be continued…

Plasma cutting steel

admin — Thu, 11 Mar 2010 11:26:36 +0000

Plasma, sometimes called the fourth state of matter, makes tech-people fascinated with it’s numerous properties. Some of them are interesting just from science point of view but many have a practical behoof in the industry. And it’s still growing with a new discoveries and new amazing facilities. Also when it comes to steel machining and cutting – plasma gives a fair competition ever to a laser cutting.

Plasma cutting machines are dedicated for manual and automated handling. Plasma and air jumble is useful with cutting electrical conducting parts made of steel, alloys, aluminium and it’s alloys, coppers, brasses and even a cast iron. Plasma cutting machines shows it’s versatile also when it comes to different enviromental conditions allowing to cut deep underwater for example. Coeval plasma machines are usually instant ready to use and with special accesories can cut in places with limited access for the other tools.

The main advantages for plasma machines:

high speed of cutting
cutting without overheating – quick nailing
small influence in the area of cutting on the steel
narrow slit
allows to cut without overburning thin fabrics.

And here comes some disadventages:

loud work noise
strong radiation
much of exhausts – gases and fumes
Some structure degeneration in cutting area
perpendicular keeping is sometimes difficult.

Let’s see and listen some example:

Laser cutting advantages

admin — Mon, 06 Apr 2009 10:38:42 +0000

There are many advantages of cutting steel by laser so we mention just the most important things seen by customer’s eye.

fastest method for metal elements development – In most cases, elements deployed from laser cutting machine are ready to use or montage right after cutting without further machining or processing, even polishing.
narrow area affected by laser temperature – high focus of laser beam on operating area significantly limits side effects of high temperature. Thanks to that the structural features of steel are not changed by temperature (no crispness increase)
minimize wastes – computer programmed track of laser movement (CNC) allow to maximize usage of material which can compensate higher cutting costs (in comparison to classic ways of cutting steel). Useless trash and wasted material can be reduced to minimum.
repetitiveness of cutting process – laser header (lens) operates without physical contact with cutted material. Thanks to that there are no deterioration effect of cutting header during the process. In conjunction with computer steering, we can receive same looking elements with exact same features during the process and between succeeding production stages.
laser cutting machines are great for singular, unique products and high number series production. It’s easy to make project on computer screen, test ready product, and make quick corrections if there are any required.

Laser cutting features

admin — Wed, 01 Apr 2009 11:20:05 +0000

For some certain reasons there are no perfect ways to machining so hard materials as steel and that’s why there are still many people on researching side. They are looking for more and more universal solutions and not to expensive at same time with high precision and accuracy. Flexibility and eventuality for setting up the whole kit to the individual purposes and preferences is very important value also. So we should have the knowledge about some limitations of technologies we choose to reach our goals. It is important if you are going to buy laser cutting machine for your purpose. Some promotional flayers are tend to avoid this kind of information, focusing on adventages only. Here are some important info for you:

in most cases, minimal radius of the the hole made by laser beam is equal to half of steel sheet thickness.
the quality (smoothness) of cutted edge for the final products (elements) in most cases when meagre sheets are machined. With the increasing thickness of steel sheets the edge can not be so smooths, and further processing can be required sometimes. It is caused by the laser beam power so if you are going to cut thicker material you need more power than declared “highest values” in machine specification manual.
the most of cutting machines doesn’t allow to set up laser beam axis so you can cut in the right angle only.

Laser Cutting Basics

admin — Wed, 25 Mar 2009 11:35:31 +0000

Laser cutting of steel sheets can be applied to differend kinds of material like: rustless steel, acid-resisting steel and aluminum. Actually, cutting by laser is not limited to stell only – also wood and synthetic can be processed. The most important advance of cutting by laser is the highest quality of the final elements and ultimate precision of developed elements. They usually need no further processing and in most cases are ready to use right after taking out of the machine. And this si the crucial moment when it comes to setting the price.

Automated process of optimise cutting way can save the material in the way no other method can stand with. Average quality of edge cutted by the laser is very smooth and the accuracy is keep at 0,01 parts of the milimeter). Thanks to the computer driven laser beam patch the waste can be pressed to the minimum. Movements of the laser beam during the process are quick, which means very quick delivery time but also minimizes the termical influence on the material so it preserves natural steels features as much possible.