ESR - Electroslag Remelting Mailversion_2012-10-09.pdf · ESR - Electroslag Remelting 3 The Electroslag Remelting (ESR) Process has been developed and introduced as a production process

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ESR - Electroslag RemeltingVersion 07/2012

ESR - Electroslag Remelting2

Have an eye on...INTECO special melting technologies

INTRODUCTION

INTECO special melting technologies GmbH has been found-ed in 1973 as a wholly private company with the objective to provide supply and services to the metals and related indust-ries worldwide.

Since its foundation INTECO special melting technologies GmbH has been engaged in Electroslag Remelting Techno-logy and Plant Design. INTECO’s key personnel has taken an active part in the development of the process since 1963 and its implementation on production scale.

A number of breakthrough technologies (mostly patented) in the field of Special Metallurgy and Remelting Technologies have been introduced to the specialty metal producing indus-try by INTECO such as ESRR - Electroslag Rapid Remelting, Mold Current Conducting, ESR Protective Atmosphere, etc.

LOCATION Headquarter

INTECO special melting technologies GmbHWiener Strasse 25A-8600 Bruck a. d. MurAUSTRIA – EUROPE

Phone: +43 (0) 3862 53 110-0Fax: +43 (0) 3862 53 844E-mail: [email protected]: www.inteco.at

ESR - Electroslag Remelting 3

The Electroslag Remelting (ESR) Process has been developed and introduced as a production process for high grade steel in-gots in 1958 in the Soviet Union, and is being applied in Western Europe since 1966. In the 1960‘s, independent research in the field of ESR has been done in Austria and Great Britain. At the same time, the first ESR-plants have been installed in Western Europe and the US on an industrial scale basis.

Since then the production capacity for ESR-steel has reached more than 1,200,000 tons per year. Although secondary liquid metal refining processes have been able to replace the ESR-process to some extent for a variety of products, the ESR-pro-cess is still gaining increasing importance when control of solidi-fication in regard to macro- and microstructure as well as higher cleanliness levels are required.

Another considerable advantage of ESR compared to conventi-onal ingot casting is the increased yield, which gains importance with an increasing ingot diameter.

In Electro Slag Remelting, a new remelted ingot is formed in a water cooled copper mold by remelting a consumable electrode in a superheated slag bath. The heat required to melt the elec-trode is produced when current passes through the liquid slag by its electrical resistance. The melting rate of the consumable electrode is controlled by the power input to the slag pool.

By choosing suitable conditions the depth and shape of the li-quid metal pool can be controlled as such that homogeneous and segregation free ingots are obtained. The liquid metal drop-lets formed at the tip of the electrode pass through the superhe-ated, metalurgically active liquid slag, thereby creating excellent conditions for slag-metal reactions, such as removal of sulphur and oxygen.

Advantages of ESR - Electroslag Re-melting compared to conventionally cast ingots

Dense Structure of ingot without in-ner shrinkhole or porosity

Higher cleanliness (less and smaller inclusions)

Homogenous structure and chemi-cal analysis over the whole ingot length

Higher yield of remelted material to final product

General improvement of mechani-cal properties

Smooth surface (in general no treat-ment of surface before hot working necessary)

Controlled soldification (improved macro- and microstructure)

Protection of remelted material against the oxidizing atmosphere by means of the slag bath

Have an eye on...ESR - Electroslag Remelting


When the process was first introduced, the ingots were produced in a static water-cooled mold from a single elec-trode. Today modern ESR installations are often provided with short collar molds and the possibility of electrode change, so that long ingots can be produced, indepen-dently of mold and electrode length. However, for the pro-duction of large size ingots, electrode change is also used in static mold furnaces. It can also be useful to combine static and short collar mold remelting in one plant. Depen-ding on the application, the concept insuring highest flexi-bility and productivity is chosen. Respectively, production parameters such as slag consumption per ton (Fig. 2), yield of good ingot material (Fig. 3) and overall conversi-on costs for the ESR operation are optimized.

ESR - Electroslag Remelting

Fig.2: Slag consumption per ton of ESR-ingot depending on ingot length for different ingot diameters

Fig.1: The production capacity of standard ESR-plants in depen-dence on ingot length for different ingot diameters

Fig.3: Good useable part of the ingot body without bottom and top in dependence on ingot diameter and length


Main Features & Characteristics of the INTECOESR-Equipment and Process Technology

MODULAR SYSTEM results in high flexibility in response to customer‘s requi-rements at moderate capital investment, shortens delive-ry and erection time of equipment and ensures a simple and smooth start-up.

PRODUCTION OF LONG INGOTS by application of electrode change. Thereby ingots up to 9 meters length and more can be produced from a multi-ple of short electrodes in a short mold.

BACKSTROKE in collar mold operation results in improved ingot sur-face.

XY-ADJUSTMENT ensures centering of electrode even in case of misalign-ment during stub welding or bended electrodes.

LOAD CELL SYSTEM results in max. weighing accuracy due to minimized dead weight and no influence of any friction forces.

SLIDING HIGH CURRENT CONTACTS result in a short bus system, which as a consequence leads to comparably low resistance and inductive losses.

COAXIAL HIGH CURRENT LOOP ensures a minimal electromagnetic field and minimizes the potential for undesireable liquid metal pool turbulan-ces.

SMART COMPUTERIZED CONTROL SYSTEM automatically finds and maintains proper operating condi-tions and thereby ensures a close control of meltrate at a defined immersion depth of the electrode irrespective of changes in electrode cross section or slag resistance.

CONTINUOUS VOLTAGE AND / OR CURRENT CON-TROL of the power supply represents the basis for a close con-trol of the process.

RADAR BATH LEVEL MEASUREMENT SYSTEM enables permanent detection of the liquid slag pool in the short collar mold.

145 t ESR plant


Plant Configurations

The INTECO modular system provides the possibility to build a large variety of plant configurations from standar-dized components and assemblies. Thereby the plant can be tailored closely to customers’ requirements in an efficient manner at moderate expense.

In principle, for standard ESR operation the following ba-sic configurations are presented in this brochure, each having its particular fields of application from an ingot weight of 0,5 t up to 250 t and more:

Plant with short collar mold / retractable baseplate

Plant with static mold

Combined concepts (short collar mold and static mold)

Pressure ESR

ESR for hollow ingots in short collar mold

ESR for slab ingots in static and short collar mold

In addition to the above specialized versions of the pro-cess are available:

Electroslag Rapid Remelting ESRR®

Current Conductive Mold (CCM®)


Plants with Short Collar Mold / Retractable Baseplate

This plant configuration consists of a fixed collar mold ar-ranged at the level of the working platform, an automatic electrode change system and a retractable baseplate with ingot car to withdraw the remelted ingot from the mold and to remove it from underneath the plant.

This arrangement is recommended for the production of comparably long ingots in excess of 2,5 m and up to 6,0 m and more.

The Retractable Baseplate System is best suited for the production of long ingots. The longer the ingot, the high-er is the productivity of the plant. Independent on ingot length easy access to the mold fixed in the operation plat-form is secured.

This configuration very well combines a high degree of flexibility and a favourable parallel or coaxial arrangement of the high current loop. Thermal insulation of the bottom part of the ingot during remelting can be realized by me-ans of a heat shield manipulator.

30 t short collar mould plant


Plants with Static Mold (with/without Electrode Change)

Static mold / single electrode plants are preferably ins-talled when comparably short ingots (low length/diameter ratio) are required. In order to reduce down time, such plants are usually equipped with two melt stations and one swiveling pylon with the electrode carriage. In that case, remelting can proceed in one melt station, while in the second melt station the ingot is removed and the sta-tion is prepared for the next melt.

Static mold plants without electrode change require com-parably long electrodes.

This configuration is therefore preferably applied when high flexibility is not required and standard size ingots of one or maximum two different sections with standard length are to be produced.

The arrangement of two melt stations helps to improve the productivity of the plant as the next ingot can be star-ted immediately after hottopping of the previous ingot has been finished. With the static mold system in general a 100% coaxial bus bar arrangement is applied.

Static mold plants without electrode change

30 t static mould plant


For ingot weights of 50 t up to 250 t and more, longitu-dinally moveable carriages (furnace heads) are used for carrying the electrode and the protective gas hood. For the production of such big ingots, electrode change tech-nology is used. Several smaller electrodes are remelted to one big ingot by alternating use of two furnace heads. Inteco’s unique experience in electrode change technolo-gy for big static mold ingots guarantees the reliable pro-duction of a superior quality product.

The Static Mold System results in the lowest capital in-vestment for the plant for a given ingot size. The higher costs of the static molds, however, may well compensate for this advantage in case a number of different mold sec-tions are required.

Static mold plants with electrode change

250 t static mould plant


Combined Plants (Short Collar Mold and Static Mold)

For applications where great flexibility regarding elect-rode dimensions, ingot dimensions, and steel grades is required, it makes sense to choose a combined furnace concept.

For the production of larger ingots using multiple elect-rodes one central meltstation (short collar mold or static mold) is installed,. As electrode change is applied, two furnace heads are required.

One or two outer static mold meltstations are installed beside the central meltstation within the range of the res-pective furnace head.

A split power supply is installed, which enables simultane-ous remelting in the outer stations. Furthermore, the pos-sibility to install a CCM® for the short collar mold meltsta-tion (if installed) exists.

36 t combined plant 150 t combined plant


Pressure Electroslag Remelting (P-ESR)

Nitrogen, besides hydrogen and oxygen, is a gaseous element which is soluble in iron, nickel and cobalt and its alloys. While oxygen and hydrogen are not desirable at all, nitrogen is used as an alloying element in particular cases for enhancing steel properties.

Since approximately 60 years, the austenite stabilizing effect of nitrogen is used on the one hand to save nickel and on the other hand to improve certain physical pro-perties of the metal, in particular of corrosion resistant austenitic steels.

The solubility of the biatomic gas nitrogen in iron at con-stant temperature is proportional to the square root of its partial pressure in the gas phase. In transition from the gas phase into solution, the biatomic nitrogen molecules are split up into two individual atoms which will be dissol-ved in the metal phase.

A direct transfer from the atmosphere into the liquid me-tals is not possible in ESR, as the liquid metal at the elec-trode tip as well as at the pool surface is covered by the liquid slag and shielded against a direct contact with the gas phase. Due to the extremely low nitrogen solubility in standard slags applied in ESR, a mass transfer of nitro-gen from the gas phase to slag and further on to metals (in contrary to hydrogen) does not occur.

Therefore nitrogen has to be supplied continuously during remelting by means of solid nitrogen-containing additives (e.g. Si3N4 or FeCrN). A major possibility to increase the solubility in liquid steel is to increase the atmospheric pressure in the system. The pressure level applied in the P-ESR process mainly depends on the requested nitro-gen content of the remelted ingot.

The control of the P-ESR process is based on the same principles as the standard conventional electroslag re-melting process, as the properties of the slag bath and hence the type of current transfer are not influenced by the atmospheric pressure above the slag.

9,5 t pressure ESR plant


ESR for Hollow Ingots in Short Collar Mold

The production of hollow ingots is a special application of ESR. A lot of research has been made in this field and Inteco is able to provide a well-engineered solution for in-dustrial scale production of hollow ingots in a broad vari-ety of lengths and diameters. Features like protective gas operation, electrode change and coaxial current flow is of course considered. Most of the existing Inteco combined ESR furnaces can be equipped with a hollow mold at a la-ter stage and for new plants, the short collar hollow mold can be designed according to customer’s requirements. During development of the hollow mold, Inteco focused especially on highest production capacity and safety as well as moderate hardware costs. Typical short collar mould for hollow ingots


ESR for Slab Ingots in Static and Short Collar Mold

Traditionally, ESR ingots are produced mainly in round shape. Nevertheless, also square and rectangular sec-tions are demanded. Recently, the production of large sized slabs with an ingot weight of 80 tons and more is requested by customers from all over the world. Inteco’s wide experience in slab ESR in short collar as well as in static mold allows tailor made concepts for the indi-vidual requirements. Sections of a smaller size (e.g. 250 x 250 mm) are very well covered with Inteco’s ESRR®

concept for maximum productivity. Bigger sections up to 2600 x 1000 mm and more demand plants with highest technology regarding mechanical, electrical as well as automation technology.

Of course, Inteco’s slab ESR plants are equipped with state of the art features like protective gas atmosphere, coaxial high current loop etc. A broad variety of shapes such as round cornered rectangle or square, chamfered corner or any other shape can be provided.

ESR slab ingot 950 x 550 mm 80 t slab ESR plant


Have an eye on...INTECO‘s specialized remelting solutions

ESRR® – Electroslag Rapid Remelting

The ESRR process has been developed to enable the production of near net shaped billets from segregation prone alloys at comparably high melt rates (compared to ESR) and without center soundness defects (compared to continuous casting).

As shown in the figure, there is a huge gap between the working ranges of ESR and continuous casting, as far as melt rates and liquid metal pool depth are concerned. In this gap lies the working range of ESRR®, combining some major advantages of both processes.

The ESRR® process generates near net shaped billets instead of ingots, with the same excellent material pro-perties of ingots from conventional ESR. Thus, the semi finished product can directly be rolled in a bar mill to the requested diameter, omitting the pricy forging process. The produced billets are dense, free of any porosity and for most commercial alloys free of macro segregation.

Due to the direct relation between power input through the electrode and the liquid metal pool shape the stan-dard ESR process has certain limits regarding choice of the appropriate melt rate for a certain application. There-fore the following solutions have been developed and are presented hereafter.


ESRR® - Electroslag Rapid Remelting

The main differences between ESRR® and conventional ESR are:

Practically, ESRR® is the conventional process tur-ned “upside down”. This means that according to the special geometry of the T-shaped mold, electrodes with a larger diameter than the billet diameter can be remelted. If the near net shaped billets had to be produced in conventional ESR, the electrodes would have to have very small diameters. It is extremely difficult and expensive to produce such electrodes.

For conventional ESR, an approximate value for the melt rate can be determined according to the fol-lowing empirical equation:diameter of ingot [mm] = melt rate [kg/h]For the production of near net shaped billets in con-ventional ESR, this would lead to extremely low melt rates of 100 – 200 kg/h, especially for segregation prone alloys. The big benefit of ESRR® is that according to the special mold geometry and the different high current path, considerably higher melt rates can be obtained without having a negative effect on the ingot struc-ture; approx. 2 – 4 times of the above mentioned value. This, along with the possibility of continuous production, leads to a remarkable enlargement of the plant productivity, making electroslag remelting for near net shaped products feasible.

A separate withdrawal and cutting equipment in conjunction with the possibility of automatic electro-de change during the ESRR® process is the most favourable configuration, as it allows a continuous operation resulting in highest productivity and lowest operating costs.

6500 mm ESRR® plant


A schematic of a typical setup of an ESRR® plant is shown in the beside figure, the ESRR® process utilizes a bigger sized electrode to produce the small sized billets. For that reason, a water cooled T-shaped mold is used. The lower, narrow part is defined by the billet section to be produced, which can be round, square, hexagonal etc., while the up-per, wider part is defined by the maximum cross section of the consumable electrode.

The consumable electrode, like in the standard ESR pro-cess is melting in the super heated slag bath, when elec-tric current is passed through. The liquid metal droplets dripping off the electrode tip are collected in the narrow, lower part of the mold, where the initial solidification takes place and the remelted billet is continuously formed.

ESRR® - Electroslag Rapid Remelting

In case of ESRR® operation, the electric current passes from the electrode tip into the slag pool and is returned partially through the mold walls by the application of un-cooled conductive elements as well as through the remel-ted ingot. The power distribution is as such, that approx. 80-90 % of the total current is transferred through the mold walls and only 10-20 % through the remelted billet.

Combining the specially designed T-shaped mold with the described current split, results in a metal pool shape, which is independent from the total power input. Hence, high meltrates can be applied and a controlled way of so-lidification, positively affecting the ingot structure, can be obtained at the same time.

In continuous operation the remelted billet is withdrawn by means of a separate withdrawal and cutting equipment, similar as applied for the continuous casting process.

Big sized electrode

Economic production of high quality near net shaped sized remelted billets

Increased melt rate as compared to standard ESR

Metal pool shape independent of amount of power input

Highest productivity in case of continuous operation

9300 mm ESRR® plant


INTECO‘s specialized remelting solutionsCCM®, Current Conductive Mold

A new current conductive mold concept, developed and patented by INTECO offers a variety of new possibilities which are yet to be explored. The possibility to directly heat the slag pool, by means of a current conductive element, offers an independent and separate control of the temperature of the slag and the rate of remelting. De-pending on the chosen split of power input through the electrode, respectively through the slag pool, a shallower liquid metal pool can be achieved.

Depending on the mode of switching and the arrange-ment of power supplies a variety of concepts are possib-le, for all of them. Meltrate, slag temperature and heat dis-tribution in the slag pool can be controlled independently from each other. Hence, ingots out of segregation prone alloys can be produced, at extremely low meltrates with an acceptable surface and a good solidification structure. In the past INTECO‘s R&D department showed several innovative ESR-developments and is quite convinced

that this new development will give all our costumers a remarkable advantage to their competitors.

Several trials have already shown the high technical po-tential of the new technology, which can be utilized in existing plants designed and supplied by INTECO.

INTECO current conductive mould

Principle of CCM® Standard ESR- and CCM® pool sizes


INTECO Features:Protective Gas Operation

In the past, the standard ESR operation was carried out without isolation from the atmosphere. This resulted in a potential for pick up of hydrogen and oxygen. Simple shielding systems which leave a gap between electrode and cover were not very efficient unless very high protec-tive gas flow rates were applied. For cost reasons, this is only possible with dry air which can prevent hydrogen pick up but oxidizing still remains. If an inert atmosphere such as nitrogen or argon is required a more efficient sys-tem becomes necessary.

For this reason INTECO has developed a protective gas ESR hood which provides a proper seal on top of the mold as well as against the electrode power ram. Today this trend towards ESR under protective atmosphere is remarkable and represents a state-of-the-art feature of al-most all recently installed ESR-plants. All INTECO plants are equipped with a rigid, water-cooled, gas-tight protecti-ve gas hood, which enables remelting of the consumable electrode in a completely closed chamber.

Ultra clean steel

Minimized hydrogen pick up

Remelting of steel with low Si and/or Al contents

Remelting of Ti-stabilized steels

Close control of analysis from bottom to top of ingot

INTECO protective gas hood


Protective Gas Operation

The hood contains a gas tight seal through which a power ram moves in vertical direction. Remelting in these plants is carried out under practically oxygen free nitrogen or argon atmosphere, or a mixture of both. Although the pro-tective gas hood is opened for electrode change, remel-ting is executed under absolutely controlled atmosphere conditions without any effect of the air for the following reasons:

The main source for the introduction of oxygen into the system is the scale formed on the surface of the consu-mable electrode in open air remelting. In the plants de-scribed here, remelting of the first electrode is carried out under oxygenfree controlled atmosphere. For this reason no scale formation takes place on the electrode surface and no heavy metal oxides are transferred into the slag.

During the time of electrode change air has access to the slag surface. The slag, however, safely protects the liquid metal pool surface from the oxygen in the air. Before the new electrode starts to melt, the hood is closed again and the protective atmosphere is reestablished so that again no scale formation will take place.

Oxygen control after electrode change


INTECO Features:Coaxial High Current Loop

Due to the low voltages and high currents applied in elect-roslag remelting, the configuration of the high current loop in the ESR plant influences the resistance and losses of the plant considerably. While resistance losses increa-se power consumption and thereby operating costs, the inductive losses effect the size of the transformer and power factor correction system which in turn influences capital investment.

INTECO’s coaxial arrangements of the high current loop ensures minimum resistive and inductive losses. The feed-in and return line from power supply to the plant are made by multiple standardized water cooled copper tubes which are arranged as such that the respective alterna-ting electromagnetic fields are compensating each other. Within the plant, multiple water cooled vertical Cu-tubes are arranged in a coaxial configuration at the shortest possible distance from electrode and ingot, respectively. The diameter of the Cu-tubes is chosen in dependence on the current requirement of the plant. Sliding contacts connect the vertical copper tube and the short bus bar system, which is connected to the high current clamps for electrode and base plate respectively. This arrangement ensures a minimum possible length of the high current loop at any electrode/ingot configuration, always resulting in the lowest possible resistance losses. The system also minimizes areas enclosed by the feed-in and return lines thereby minimizing the inductive losses. For other plant configurations like movable mold or static crucible the system is adapted accordingly.

Decreased high current loop length

Minimized electromagnetic field

Diminishes the potential for undesirable liquid metal pool turbulences

Minimizes inductive resistance

Lowest energy consumption

High current loop Connection to power supply


INTECO Features:Weighing System and XY-Adjustment

The aim of the ESR-process is to produce ingots at a de-fined meltrate under the condition of a defined depth of immersion of the consumable electrode into the slag pool. In order to calculate and control the exact and desired meltrate, INTECO has developed an innovative weighing system.

The load cell system is mounted on the top plate of the XY-adjustment system and consists of three load cells, on top of which the weighing plate is sitting, which is secured against a sideways dislocation. On top of the weighing plate the electrode clamping device is mounted.

Maximum weighing accuracy

No influence of friction forces

Minimized dead weight

The load cell system consists of three load cells, accuracy class 0.03 and three pendulum supports, a terminal box in order to connect the three signal conduit lines, three earthing cables to protect the load cells against currents from welding operations, lightning, etc., a shielded, low capacity special cable as well as a weighing processor.

This system guarantees an exact electrode weight mea-surement during the whole remelting process resulting in very accurate meltrate control and thereby resulting in superior ingot quality.

Weighing system + XY-adjustment Weighing system + XY-adjustment


INTECO Features:Control System

It is the aim of the ESR-process to produce ingots at a defined meltrate under the condition of a defined depth of immersion of the consumable electrode into the slag pool. The conditions therefore are given only if all the pa-rameters that have an effect on meltrate and immersion depth are kept constant. These parameters are voltage, current, power and electrode cross section, preheating of the electrode tip along the whole length of the electrode, specific resistivity of the slag pool during the entire re-melting cycle etc. In practical plant operation, however a change of conditions and parameters over an extended period of time cannot be avoided.

Control of plant functions

Control of remelting process Constant meltrate Predefined shallow immersion depth of electrode Independent of operation skill

Data handling and database functions (requirements of a modern automation)

Therefore, a simple control system cannot be sufficient and successful in achieving a constantly predetermined meltrate at a defined depth of electrode immersion at any time of the operation. The control system developed by INTECO which has been installed and steadily improved in many ESR-furnaces within the last decades contains a modern automation and process control system, which meets the following requirements: Control of plant func-tions and remelting process as well as data handling and database function.

Typical documentation sheet


Control System

As far as the remelting stage is concerned, the control system takes control over the process from the very start to the end, by means of predefined starting- and hot-top-ping curves. The operator can choose in which way the remelting should be done.

During starting and hottopping phase the melting current and voltage follow a predefined curve. In the prescription for the melt the duration of the respective phase and the respective curve are defined. During execution it is always possible to shorten or prolong these curves or change the level of current and voltage. Voltage and Current Cont-roller act directly on the power supply and the electrode

speed controller of the furnace. The assignment of the controllers is given by the principle of the power supply (current or voltage source).

During steady state operation two superimposed cont-rollers affect the setpoints of the power supply and mo-vement controller in order to obtain the desired melting characteristic. In most cases, meltrate control will be pre-ferred, but in case of a failure of the weighing system, power control may be used. To control the immersion depth the swing controller, which is based on the effect of the dependency of current or voltage variation from the immersion depth, will be selected.

Typical control system setup


The control system automatically detects the actual re-melting phase (slag melting, starting, steady state) and acts accordingly. Special controller settings and controlled feed of start slag are crucial for a reliable and efficient slag melting and starting process. The intelligent cooling water system ensures extended lifetime of copper parts at the process start as well as ideal remelting conditions during steady state.Acoustic and visual notification ensures that accompa-nying tasks (e.g. electrode preheating, aftercooling ) are done at the right time and no production capacity is lost.

Control System

Basic Scheme of an ESR-plant

Starting- and hot topping curve

Main control systemTypical remelting trend


A database driven support system provides detailed plan-ning and analyzing features and is therefore an ideal tool for production planning and quality assurance.

Proven methods in remelting a certain steelgrade are stored in recipes to ensure repeatable processing condi-tions. Prescriptions for multiple heats can be prepared in advanced and retrieved on demand.

Control System

Remelting figures and trend curves for all quality related parameters are stored in a long term data structure and available for detailed analysis. Standard reports can be retrieved for single heats and weekly or monthly produc-tion.

Typical screenshots of the control system


Have an eye on...INTECO‘s Large Size ESR-Plants

Recently, a huge demand for ESR – furnaces, designed for the production of ingots with comparably large dia-meters and weight, has evolved. Especially producers of equipment for the power generation industry (e.g. turbines, rotors, pressure vessels,…) have discovered the advantages of ESR – remelted semi-finished goods for their applications. Until today, it is common practice to use ingots produced by conventional ingot casting as input material for the forging process and the sequential production steps. A comparison of conventional ingot cas-ting and ESR shows that ESR is favorable in regard of the following aspects:

In ESR a considerably higher yield of > 90% can be achieved, compared to ingot casting (approx. 70%).

The ESR process improves cleanliness and mechani-cal properties of the produced ingot.

Furthermore ESR ingots are more dense and homo-genous. This leads to smaller hot forming factors as opposed to conventionally cast ingots.

Regarding the design of such a plant the large weights of electrodes as well as ingots has to be taken into conside-ration. Furthermore the power supply concept has to be adjusted to the given application.

145 t combined ESR plant


INTECO‘s Large Size ESR-Plants

INTECO has developed a general concept which meets the requirements of the production of such ingots. Aside from the state-of-the-art features which all INTECO re-melting furnaces have, the large size furnaces are equip-ped with the following:

For static reasons, the furnace head is done in a portal carriage design. The cantilever design which is normally used is not convenient for electrodes with a weight ex-ceeding 16 tons for plants using electrode change tech-nique.

For plants in short collar mold design, the retractable base plate needs to be adapted. This means that the number of spindles must be increased and the steel construction has to be adjusted to the ingot weight.

If the remelting process is using electrode change tech-nique (several electrodes are remelted into one ingot), the electrode tips must be preheated prior to electrode change. Furthermore, the procedure of electrode change must be kept as short as possible. Hence, a special con-cept has been developed for a station which enables electrode loading, stub and electrode rest disc unloading as well as preheating of the electrode tip.

145 t combined ESR plant (© Saarschmiede GmbH)


Short collar mold melt stations are equipped with a slag breaking device, in order to increase the safety and pre-vent major damage in case of a slag breakout.

In case crack sensitive materials are remelted in a furna-ce with short collar mold melt station and retractable base plate, a heat shield manipulator can be installed. This de-vice avoids a too quick cooling of the remelted ingot and minimizes the danger of cracking.

INTECO‘s Large Size ESR-Plants

It is also possible to implement the Current Conductive Mold (CCM®) Technology for short collar molds in order to be able to remelt segregation prone alloys into ingots with large diameters at comparably low melt rates.

Two different types of vertical stub welding equipment exist. On the one hand, the well known butt welding pro-cess is available, on the other hand, a new concept using MIG/MAG welding robots has been established.

250 t static mould ESR plant


Increased productivity due to flexible use of inner fur-nace heads

Low maintenance costs due to special and well pro-ven design of high current sliding contact

Very reliable 100% coaxial high current flow in the re-turn line due to special designed base plate clamping method

Low specific energy consumption due to short high current loop and the use of large copper sections for the bus system.

The INTECO furnace head design allows electrode change operation in static mold as well as in short collar mold operation

Seperate MCC‘s and control cabinets, mounted on each furnace head allow a reduction of mutiple long special cables and the use of the furnace heads in multiple ESR-plants

Semi automatic electrode loading and stub unloading procedure is provided in combination with preheating furnace

Comfortable access during electrode-, crucible- and ingot-handling by overhead travelling crane also du-ring melting

CCM® for collar molds

Slag breaking device for collar molds

Radar measurement system for slag bath height de-tection

Features

Static crucible ø 2600 mm


Have an eye on...INTECO‘s Auxiliary Equipment

For ESR production, a remelting furnace is not sufficient. There are a number of facilities you can’t do without. Inte-co is able to provide all necessary equipment for running an ESR shop such as:

Vertical and horizontal stub welding devices

Shot blasting equipment

Heat treatment furnaces

Slag breaking devices

Ingot- and electrode cutting equipment

Mold cleaning units

Rest disc cutting devices

Ingot cooling hoods

Considering the whole ESR production cycle, INTECO is the No.1 turn key supplier of your ESR melt shop.

Vertical robot stub welding unit


INTECO Selected ReferencesAllvac Monroe, USALabscale ESR / VAR furnace

Type ESR / VARMeltstation(s) One (1) combined meltstation

for ESR and VAR operationMax. ingot diameter 200 mm ESR / 250 mm VARMax. ingot length 1450 mmMax. ingot weight 360 kgPower supply Combined AC/DC supplyFurnace Head(s) One (1)Electrode Change NoProtective Gas / Vacuumtight Hood

Yes

Fully Coaxial Design YesCustomer Allvac MonroeStart Up December 2009


INTECO Selected ReferencesThyssen Krupp VDM Unna, GermanyStatic mold

Type Static moldMeltstation(s) Two (2)Max. ingot diameter 500 mmMax. ingot length 2700 mmMax. ingot weight 4,4 tonsPower supply Saturable reactorFurnace Head(s) One (1)Protective Gas Hood YesFully Coaxial Design YesCustomer Thyssen Krupp VDM Unna Start Up December 2007


INTECO Selected ReferencesDeutsche Edelstahlwerke GmbH, Krefeld, GermanyStatic mold

Type Static moldMeltstation(s) Two (2)Max. ingot diameter 1250 mmMax. ingot length 3600 mmMax. ingot weight 30 tonsPower supply Saturable reactorFurnace Head(s) One (1)Protective Gas Hood YesFully Coaxial Design YesCustomer Edelstahl Witten-Krefeld Start Up May 2004


INTECO Selected ReferencesFOMAS Group, ItalyStatic mold with electrode change

Type Static MoldMeltstation(s) Three (3)Max. ingot diameter 1900 mmMax. ingot length 5200 mmMax. ingot weight 110 tonsPower supply TransformerFurnace Head(s) Four (4)Electrode Change YesProtective Gas Hood YesFully Coaxial Design YesCustomer FOMAS Group Start Up March 2011


INTECO Selected ReferencesForgiatura Antonio Vienna, ItalyStatic mold with electrode change

Type Static MoldMeltstation(s) Two (2)Max. ingot diameter 2600 mmMax. ingot length 6000 mmMax. ingot weight 250 tonsPower supply Cyclo ConverterFurnace Head(s) Two (2)Electrode Change YesProtective Gas Hood YesFully Coaxial Design YesCustomer Forgiatura Antonio Vienna Start Up May 2011


INTECO Selected ReferencesCarpenter Technology Corp., USAPressure ESR-Plant

Type Static mold / Pressure ESRMeltstation(s) Two (2)Max. ingot diameter 762 mmMax. ingot length 2700 mmMax. ingot weight 9,5 tonsPower supply Saturable reactorFurnace Head(s) One (1)Electrode Change NoProtective (Pressurized) Gas Hood

Yes

Fully Coaxial Design YesCustomer Carpenter Technology Corp.Start Up March 2009


INTECO Selected ReferencesSonderstahlwerk Breitenfeld, AustriaShort collar mold / retractable baseplate

Type Short collar mold*Meltstation(s) One (1)Max. ingot diameter 1200 mmMax. ingot length 4000 mmMax. ingot weight 36 tonsPower supply TransformerFurnace Head(s) Two (2)Electrode Change YesProtective Gas Hood YesFully Coaxial Design YesCurrent Conductive Mold PossibleCustomer Sonderstahlwerk Breitenfeld Start Up September 2003

* Optional small central static mold for super alloys


INTECO Selected ReferencesKind&Co Edelstahlwerk, GermanyShort collar mold and static mold

Type Short collar / Static moldMeltstation(s) Three (3)Max. ingot diameter 1000 mmMax. ingot length 4000 mmMax. ingot weight 30 tonsPower supply TransformerFurnace Head(s) Two (2)Electrode Change YesProtective Gas Hood YesFully Coaxial Design YesCurrent Conductive Mold PossibleCustomer Kind&Co EdelstahlwerkStart Up April 2004


INTECO Selected ReferencesFushun Special Steel, ChinaShort collar mold and static mold

Type Short collar / Static moldMeltstation(s) Two (2)Max. ingot diameter 1000 mmMax. ingot length 5500 mmMax. ingot weight 34 tonsPower supply TransformerFurnace Head(s) Two (2)Electrode Change YesProtective Gas Hood YesFully Coaxial Design YesCurrent Conductive Mold PossibleCustomer Fushun Special Steel Co. Ltd.Start Up November 2011


INTECO Selected ReferencesSaarschmiede GmbH, GermanyShort collar mold / retractable baseplate and static mold

Type Combined Plant*Meltstation(s) One (1) short collar mold +

Three (3) static moldMax. ingot diameter 1900 mmMax. ingot length 6500 mmMax. ingot weight 145 tonsPower supply Saturable reactorFurnace Head(s) Three (3)Electrode Change YesProtective Gas Hood YesFully Coaxial Design YesCurrent Conductive Mold PossibleCustomer Saarschmiede GmbH Start Up March 2010

* Short collar mold / rectractable baseplate and static mold


INTECO Selected ReferencesDongbei Special Steel Co.Ltd., ChinaShort collar mold and static mold

Type Combined Plant* Meltstation(s) One (1) short collar mold / static

moldMax. ingot diameter 1750 mmMax. ingot length 5300 mmMax. ingot weight 100 tonsPower supply TransformerFurnace Head(s) Two (2)Electrode Change YesProtective Gas Hood YesFully Coaxial Design YesCurrent Conductive Mold PossibleCustomer Dongbei Special Steel Co.Ltd. Start Up October 2011

* Short collar mold / static mold


INTECO Selected ReferencesChangwon Speciality Steel, KoreaESR and ESRR®

Type ESR/ESRR®

Meltstation(s) One (1)Max. ingot/billet length ingot: 4 m, billet: 6 mMax. ingot weight 6.2 t (ESR), 2.7 t (ESRR®)Power supply TransformerFurnace Head(s) One (1)Protective Gas Hood Yes (Loading/Unloading Arm)Fully Coaxial Design YesCustomer Changwon Speciality SteelStart Up September 2005


INTECO Selected ReferencesAcciaierie Valbruna, ItalyESRR®

Type ESRR®

Meltstation(s) One (1)Max. billet dimension 220 mm squareMax. billet length 6500 mmMax. billet weight 2.5 tonsPower supply TransformerFurnace Head(s) One (1)Electrode Change Yes (Loading/Unloading arm)Protective Gas Hood YesCustomer Acc. ValbrunaStart Up June 2006


INTECO Selected ReferencesUgitech, FranceESRR®

Type ESRR®

Meltstation(s) One (1)Max. billet dimension 205 mm squareMax. billet length 3800 mmMax. billet weight 1.3 tonsPower supply TransformerFurnace Head(s) One (1)Electrode Change Yes (Loading/Unloading arm)Protective Gas Hood YesCustomer UgitechStart Up July 2007


INTECO Selected ReferencesXingtai Iron & Steel Corporation Ltd., ChinaESR + ESRR®

Type ESR + ESRR®Meltstation(s) One (1)Max. billet dimension dia. 600 mm ingot /

160 mm square billetMax. billet length 4000 mm (ESR),

9300 mm (ESRR®)Max. billet weight 8,9 tons (ESR)

1.66 tons (ESRR®)Power supply Saturable reactorFurnace Head(s) One (1)Electrode Change Yes (Loading/Unloading arm)Protective Gas Hood YesCustomer Xingtai Iron & Steel CorporationStart Up April 2012



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Europe

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South America

Europe

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Documents

ESR - Electroslag Remelting Mailversion_2012-10-09.pdf · ESR - Electroslag Remelting 3 The Electroslag Remelting (ESR) Process has been developed and introduced as a production process