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Metalworking/Automotive

Metalworking The road from extracting mineral produced are supplied to this industry. Metalworking is a vast industry from to a finished product is very Not only is the automotive industry a covering a broad spectrum of process long and more or less every step needs large consumer of metal components, stages. These range from actually some sort of cooling and heating. it is also an industry with very high producing a metal to finishing an end- quality demands. This is an advantage product, such as a door handle on a When it comes to service fluids for for Alfa Laval, a company which fulfills car or a cold drink can. metalworking, Alfa Laval has extensive and all qualitative developments process know-how that will save within plate heat exchanger Correct temperature control of service customers money. manufacturing. fluids within the metalworking industry can have a huge impact on plant Automotive Alfa Laval also supplies temperature profitability. Service fluids are used in Metalworking is closely connected to control solutions to many processes the process of shaping the metal as the Automotive and Vehicle industry around the vehicle industry such as well as for cooling and lubricating and a large volume of the dynamometers, wind tunnels and machinery used for shaping metal and cast and finished components testing. materials.

Various steps of typical surface treatment and metalworking operations in a car plant. From mineral to material

While Alfa Laval supplies heat transfer equipment to the first step of the making process, the company delivers far more industrial components to the second step where molten steel the process in red-hot solid slab form, becomes a component. This is also the and is then cut to the desired length. part where system builders around the world supply equipment for metal Hot strip mill sheets (which are often coiled at the shaping. The majority of these systems Rolling is the main method used to end of the process). First the slabs and machines incorporate coolers and shape steel into different products. The from the caster are reheated in the heaters of various kinds. rolling process consists of passing the re-heat furnace. After this they are steel between two rolls revolving at the moved, one by one, on a conveyor to Caster same speed but in opposite directions. the hot rolling mill. Here the slabs are In the caster molten steel is turned into The gap between the rolls is smaller rolled as often as necessary to reach solid stabs of steel and themost than the steel being rolled, so that the the desired measures. After rolling, the common process is continuous steel is reduced in thickness and at the steel is normally pickled to remove casting. From the ladle the molten steel same time lengthened. Two rolls from the surface. At this point, flows into the tundish of a caster from opposite to each other together are some products, such as steel plates, where it then flows into the caster’s called a “stand”. A rolling mill may may be ready for shipping, but most of water-cooled mould. As the steel consist of up to 10 or more stands. the products have to be further treated travels down the caster, it solidifies with by a process. This is the help of water sprays. The steel Hot rolling is a hot working process. often called cold rolling, but for wire comes out of the caster at the end of Here a cast slab is converted into and tubes is also is usual. Pickling line Products Pickling prepares the surface for further better thickness tolerances and less The final product from this industry can processes. Pickling removes oxides oxidation. As a final stage and between be a sheet, a bar (round or rectangular), from the surface by immersion in an cold rolling processes the steel may be a coil or a wire which will then be acid bath. After this the acid is rinsed annealed. further worked on in various industries. off and the steel is dried. As a final The majority of the products will also stage, the surface is oiled to protect be coated in one way or another. This further oxidation. After the cold rolling process the steel is described further below. is too hard and inflexible. Annealing Cold strip rolling mill makes the steel more suitable for Cold rolling is a cold rolling process in and . Annealing is a which the steel sheets are made heat or thermal treatment process. The thinner and formed into the desired steel is heated to a designated shape. The advantages of cold rolling temperature for a sufficient amount of compared to hot rolling are for example time and then cooled. Premium metal components

Products from the metal making various . In many metal working process are sold onward to companies The typical processes are , processes the are heat which will add value to the product and , forming, pressing and drawing treated to relieve stresses or to provide sell it as a finished product. These of the product. These operations certain other desired surface companies normally perform one or require a lot of cooling and lubrication. properties. The process is normally more of the following operations: The service fluids can be e.g., water- divided into: based , neat oils or pressing • Softening, which is normally achieved Alfa Laval supplies temperature emulsion and the functions of the fluids by heating and slow cooling control solutions for most of these include: (annealing, described earlier) processes, e.g.: • , which is normally • Cooling - - achieved by heating and rapid - cool the (tear) - - Paint cooling (, described plating - Passivating - cool the (measures) below) - Coolants - Phosphating - cool the chips (breaking) - - Pickling • Lubricating The service fluids identified with these plating - Process water - Cutting oil - Quench oil - between the tool and material two processes are normally oil and - Degreasing - Rolling oil • Transportation of swarfs process water. - Honing oil - Sintering oil - prevent tearing of machine & - Hydraulic oil - Test bed oil • prevention Induction heating - oil - Wash Heating a metal in order to create the - Lubrication oil - plating Heat treatment correct properties can be done by In the metallurgical, metal working and electromagnetic induction. This requires mechanical industry, a wide array of cooling of the electric rectifier and of heat treatments is performed on the induction coil.

Metalworking applications

Machining Heat treatment Degreasing Surface treatment Automotive Cutting Quenching Washing Phosphating Test Bed Forming Annealing Degreasing Plating Dynameters Pressing Quench Oil Water Anodizing Wind tunnels Coolants Oil Process water Solvent Painting Oil Acids Water Paint Air Quenching During , the metal part is heated in the manufacturing process, batch or oil can cause steam explosions. to 800 - 900°C in a furnace. To cool continuous. A heat exchanger is Therefore the customer wants to be the metal, avoiding oxidation, the work- needed to control the temperature of absolutely sure that no leakage piece is quenched in a tank filled with the quenching bath. between the two fluids occurs. In these quench oil or water emulsion. Due cases a double-wall PHE is often the to environmental controls and Special attention has to be paid to the preferred solution. regulations, there is a trend in many clogging problem. Particularly when countries to use synthetic oils instead quenching steel pieces, large numbers Alfa Laval can supply all these types of of the traditional mineral oils. of steel flakes or particles form a heat exchangers and several others, suspension together with the oil. In this depending on the need within the The characteristics of the quenching case a PHE with a wide channel or a application. fluid and its desired temperature vary heat exchanger may be chosen. according to the material and the type Spiral heat exchangers not only of workpieces that need to be overcome clogging but are also better quenched. Usually, baths are kept at a protected against erosion. In some temperature in the range of 40 - 70°C, installations, water mixing with quench

Cooling of quench oil utilizing a PHE for cleaner applications and a spiral heat exchanger for applications which carry a lot of dirt and particles. Surface treatment Pickling Surface treatment is a process where there can be a pre-rinsing step before Pickling is a process where oxides are the surface of the metal parts is the washing process. removed from the surface of objects. cleaned in order to add paint or (thin) This operation produces a smoother metal layers for protection against wear The type of wash used depends surface which will improve the results and corrosion as well as for decorative on the type of pollution and the of phosphating and painting. purposes. Almost all operations involve material of the workpiece. In general, fluids that need heating or cooling. water-based alkaline wash liquids are Many hot working processes and other suitable for removing particles, while processes that occur at high Due to the nature of metals, different solvent-based wash liquids are suitable temperatures leave a discolouring metals are treated and coated for removing fat and oil. layer or scale on the surface. In differently, although all metals are first order to remove the scale the washed and degreased. The diagram • Water-based wash liquids (alkaline) workpiece is dipped into a tank of below provides a guideline for the - pH from neutral to 14 pickling liquid. various steps following degreasing: - Effective particle removal - Environmentally friendly The most commonly used acid is Washing/degreasing • Solvent-based wash liquids (acid) hydrochloric acid, however The performance of the washing varies - pH 1 - 5.5 is also used. Hydrochloric acid is more depending on machining conditions as - Effective fat and oil removal expensive than sulfuric acid, but it well as the type of pollution, material, - Poor particle removal pickles much faster while minimizing demands on degree of purity, etc. In - Affects the environment loss. The speed is a general one or more wash steps are - Suitable for and requirement for integration in automatic used followed by rinsing in one or more steel mills that run production at steps. If the product is highly polluted high speed.

Plating

Mild Steel Pickling Passivating Galvanizing

Phosphating Painting

Degreasing Stainless Steel Pickling Painting

Anodizing

Light Metals Painting

Plating Carbon , with an content to achieve hard and wear resistant by heating. The traditional system less than or equal to 6%, are often surfaces (hard chromium plating) or to is to heat the bath with pickled in hydrochloric or sulfuric acid. improve the finish on the object submerged heating coils. Steels with an alloy content greater (decorative chromium, copper and than 6% must be pickled in two steps nickel plating). Phosphating and other acids are used, such as Phosphating of metals is one of the phosphoric, nitric and hydrofluoric acid. In the process the components to be most important surface treatment Rust and acid resistant chromium- plated are immersed in a solution methods and a number of modern nickel steels are pickled in a bath of called an electrolyte, containing one or metal finishing procedures would not hydrochloric and nitric acid. Most more dissolved metals. A power supply be possible without it. The main areas copper alloys are pickled in dilute supplies a current so that the dissolved of application of phosphating are: sulfuric acid, but is pickled in metal in the electrolyte solution concentrated sulfuric and nitric acid create a metallic layer on the • Corrosion protection in conjunction mixed with sodium chloride and soot. components. with organic , e.g., paints and polymer films The duty conditions for this application The plating metals can be combined in • Facilitation of cold-forming can vary greatly. The heat exchanger several layers, such as copper followed processes, e.g., and duty is temperature control by heating. by nickel plating, or nickel followed by tube drawing, deep drawing The traditional system design is to heat . • Corrosion protection in conjunction the bath with submerged heating coils. with oils and waxes The objects can be lowered into the Passivating • Corrosion protection with no tank or sprayed with the liquid. Passivating is performed to prevent subsequent treatment. oxidation. A thin layer of chromic acid Plating is applied to the surface. The objects Of the many phosphating systems Plating creates a metal layer on the can be lowered into the tank or which have been proposed, the surface of a component, often by using sprayed with the liquid. The heat following are of industrial importance: an electrolytic process. The purpose is exchanger duty is temperature control zinc phosphate, phosphate, manganese phosphate. Such phos- phating systems are predominantly applied to iron and steel, as well as zinc surfaces, whereas other metals which can be phosphated, e.g., aluminium or magnesium, are less commonly processed by this method.

Phosphate coatings which adhere well to the base metal and which, so far as possible, cover it completely, can only be formed on clean surfaces which are free from rust, scale and other corrosion products. Oil and grease films likewise inhibit phosphate

Typical cooling of batchwise surface formation, except when they are so treatment operations. thin that they are removed by an initial stage. The phosphate solution is an water by means of steam. The heated temperature, and current must be application with a high risk of scaling. water is then sent into the second PHE controlled to allow the formation of a When the phosphatizing process is not to heat the phosphating bath consistent oxide layer. Other types of in operation, the solution remaining in anodizing processes are: the PHE gets cold and a salt of zinc- Anodizing or iron-phosphate will precipitate onto Anodizing is an electrolytic process • Chromic acid anodizing the plate surface. The salt is very hard where objects are oxidated (covered by • Sulfuric acid anodizing and difficult to remove, resulting in a an oxide layer). Anodizing is used for • Organic acid anodizing frequent need to open and clean the light metals such as aluminium, • Phosphoric acid anodizing PHE. The wall temperature should be magnesium, and zinc to kept as low as possible to avoid achieve higher corrosion and wear Galvanizing deposits growing too fast on the heat resistance or to obtain a decorative is the process of applying surface. In this aspect zinc-phosphate finish. The oxide layer provides an a protective zinc coating to steel or solutions are more sensitive than iron- excellent basis for impregnation, iron, in order to prevent corrosion. phosphate. A way to prevent deposit colouring or painting. This can be achieved by hot-dip growths is to use recirculation on the galvanization or by electro-galvanization hot side, making it possible to reduce Aluminium anodizing is usually (i.e., zinc plating). It is primarily the the temperature on the hot side. If the performed in an acid solution which electrolytic process that is of interest customer wants to use steam as the slowly dissolves the . for Alfa Laval, since it involves heating heating media, it is advisable to install Conditions such as electrolyte of the bath where components are an intermediate PHE for heating of concentration, acidity, solution treated.

In surface treatment operations (and heat treatment operations) temperature regulation is . Cost effective solutions often require a combination of cooling and heating technologies (depending on the ambient temperature). Painting to handle the paint without any risk of Advantages of a Plate Heat The painting process usually consists contaminating copper ions. Exchanger of three main steps: The sizing of a heat exchanger is often • Adding a primer to prevent rust Heat exchangers in surface based on heating a fluid in the tank, • Adding a surfacer to ensure that the treatment which is called a batch calculation. The paint adheres and covers well Surface treatment normally involves most common heat exchanger in • Coating with a colour heating different process fluids in a surface treatment is a simple coil. number of tanks. This means that However, it is often an advantage to Temperature control of the paint is of multiple heat exchangers are needed replace submerged coils with external the utmost importance in order to and in many cases utility coolers are heat exchangers. provide the exact properties of the also needed. A pump normally various coatings. Alfa Laval can supply circulates the process fluid through the The advantages include: many different heat exchangers heat exchanger, which uses a cooling • Less tank and fluid volume equiredr matching different demands in this media, typically water. The cooling • No risk of damaging the coils when process. The unique Alfa Laval media can then, in turn, be cooled by objects move up and down in AlfaNova enables the paint companies a chiller or a radiator or both. the tank • Recirculation of the fluid gives stirring which decreases or eliminates the need for agitators • Easier maintenance • Stand-by unit possible (for service and breakdowns)

Adding colour to a car is a complex process and several steps are required to achieve a perfect and long-lasting finish. Automotive applications or oil-based, accurate temperature Modern vehicles have to meet control and efficient cleaning are increasingly demanding requirements essential to ensure end-product quality. relating to economical fuel Not every metalworking operation may consumption, low emissions and an include every process mentioned enjoyable driving experience. In order above but all processes involve water- to develop reliable solutions all the based or oil-based service fluids – major vehicle manufacturers and their these fluids are in short supply and are sub-suppliers have rigorous testing even scarce in many places on the facilities where they simulate operation planet. of each component. Most of these test benches and test rooms need Energy efficient products and heat temperature and climate control. recovery are other factors that strongly Alfa Laval is a well-known supplier influence total cost of ownership. within this field supplying state-of-the- art technology with a small footprint Combining these two parameters and efficient heat transfer area. makes temperature control vital for a sustainable future. Choose the right technology and help save the planet Whatever the metalworking process, whatever the service fluid, water-based