| Wire rod | [German version] |
Table of contents |
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| General: | ||
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Product information | |
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Packaging | |
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Transport | |
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Container transport | |
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Cargo securing | |
Product information
Product name
| German | Walzdraht, Drahtrollen, Drahtcoils |
| English | Wire rod, wire rod coils |
| French | Fil machine |
| Spanish | Alambre laminado |
| CN/HS number * | 72 ff. |
(* EU Combined Nomenclature/Harmonized System)
Product description
Wire rod is a rolled alloy or nonalloy steel product, produced from a semi (e.g. bloom) and having a round, rectangular or other cross-section. Particularly fine cross-sections may be achieved by subsequent cold forming (drawing). Wire rod is wound into coils and transported in this form. .
Quality / Duration of storage
The value of steel products is in particular reduced by the effects of corrosion and mechanical damage.
One particularly frequent cause of damage is rust due to seawater, rain, condensation water in the means of transport, cargo sweat or condensation inside the packaging. Unsuitable means of transport, ships with poor hatch covers or without ventilation facilities, damaged containers, uncovered railroad freight cars and trucks, incorrect storage in the open, use of unsuitable tarpaulins, exposed loading in wet weather conditions, and variations in temperature and climatic conditions during long voyages may result in rust damage.
In the case of hot-rolled steel, it is usual to store it in the open and to transport it without protection, such that no protection is provided against rain etc.. Such sheet therefore generally exhibits a layer of surface rust (rust film). Since the rust is removed from the steel (by pickling) prior to further processing, the quality of the steel is not impaired. Protection should be provided from seawater or chemical residues because corrosion must remain within reasonable bounds, since pickling cannot remove uneven local corrosion or pitting corrosion.
High-grade wires (e.g. prestretched wire or prestressed concrete wire) should be protected from all kinds of corrosion by selecting the correct packaging, warehousing and means of transport.
The degree of rusting of steel consignments should be recorded in the shipping documents before acceptance of the consignment, possibly using the following definitions:
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Wet before shipment |
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Partly rust stained to rusty |
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Gear marked |
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Contaminated by foreign substance |
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Contaminated by saltwater |
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Chafed in places |
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Packing torn exposing contents |
The AMERICAN RUST STANDARD GUIDES are mainly used to describe the condition of hot-rolled steel.
Intended use
Wire rod is used for many different products. Depending upon how it is cold formed and heat treated, wire is used, for example, to produce not only wire ropes, barbed wire, wire mesh and nails, but also springs, welded wire mesh and reinforcement wire.
Figures
(Click on the individual Figures to enlarge them.)
 Figure 1 |
 Figure 2 |
Countries of origin
Trade in steel and steel products primarily flows:
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within the EU |
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Eastern block –> EU countries and USA |
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EU countries –> USA |
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Japan, Korea, India, South Africa, Brazil –> EU countries and USA |
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Packaging
Hot-rolled wire rod is held in a unit with at least four steel straps in the transverse direction and transported and stored without further packaging. Before the steel strapping is applied, the wire rod must be sufficiently compressed. The strapping is fixed in the transverse direction with a single circumferential strap so that the strapping does not slip and cause the coil to come apart.
Special steels (e.g. prestretched wire or prestressed concrete wire) should be protected from corrosion and mechanical stresses (e.g. scratching and buckling) and are generally provided with multilayer packaging using corrosion protection (e.g. oiled or VCI paper) or film-coated packaging paper and plastic films.
 Figure 3 |
 Figure 4 |
 Figure 5 |
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Transport
Symbols
 General cargo |
Means of transport
Truck, ship, railroad
Container transport
Standard containers are suitable for containerized transport of wire coils.
The weight of the cargo should be uniformly distributed over the container floor area, while complying with the maximum weight in accordance with the CSC (Container Safety Convention) approval. The maximum line load must also be taken into account when loading containers (Container loading capacity).
Loads must be very carefully secured inside the container, since the coils must on no account be able to move.
 Figure 6 |
 Figure 7 |
Cargo handling
Cargo handling should be carried out in dry weather or under cover, since the product is highly susceptible to corrosion.
 Figure 8 |
Wire in coils must be handled carefully owing to its sensitivity to mechanical damage. Damage may be prevented by correct handling and the use of suitable handling and slinging equipment (e.g. crossbars, C hooks, coil mandrels, webbing slings, chain slings).
Lifting or setting down the wire coils with excessive force results in distortion, which is detrimental to further processing, since the wire coils can no longer be properly unwound and further processed.
The permissible loading capacity of the slinging and handling equipment and the lifting capacity of the lifting gear must also be taken into account.
In addition to purely mechanical damage to the product itself, damage to the packaging means that the product is no longer protected from moisture penetration. This may result in corrosion.
Stowage factor
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0.83 m³/t (steel wire) [1] |
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1.60 m³/t (wire rope rolls) [1] |
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2.00 m³/t (barbed wire) [1] |
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2.94 m³/t (netting wire) [1] |
Stowage space requirements
Due to its weight, this product is generally stowed in the lower hold. The loading capacity of the decks must be taken into account when drawing up the stowage plan.
The purpose of floor and interlayer dunnage is to protect the cargo and the means of transport from damage and to facilitate handling. Special floor or interlayer dunnage need not be used if the coils are already on wooden supports (coil skids).
If wire coils are secured with wedges to prevent rolling, care must be taken to produce the wedges such that the underside of the wedge (2) and inside of the wedge (1, the side facing the coil) are cut across the grain and the outside of the wedge (3, which is nailed) is cut with the grain.
Lateral dunnage is used where cargo handling has resulted in gaps in the stow. These gaps are either filled in during loading with squared lumber, planks or boards or subsequently closed by costly bracing (shoring).
Segregation
Oil-based paint (where necessary)
Cargo securing
Comply with the consignor’s/manufacturer’s loading instructions in order to avoid damage due to mechanical stresses.
Truck:
Wire rod must be transported in vehicles having a headboard and side walls (stanchions) with sufficient strength and loading capacity. Nonslip material must also be placed under the load and between layers. Gaps in the load are often unavoidable due to the handling methods used and vehicle characteristics (load distribution), so the load must be secured in accordance with anticipated accelerations by direct securing (e.g. tight fit, loop lashing) and/or by frictional securing (e.g. tie-down lashing).
For detailed information about cargo securing, see the chapter entitled Wire rod coils in the GDV Cargo Securing Manual.
For further information see also the chapters entitled
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„Basic physical principles of cargo securing“, |
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„Road vehicles, selection, equipping and loading capacity“, |
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„Cargo securing materials“. |
Ship:
The following principles apply:
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Select stowage spaces in accordance with the sensitivity of the cargo and anticipated accelerations |
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Where possible, load cargo closely against parts of the vessel or other cargo having sufficient loading capacity, but … |
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… stow and secure in such a way that no excessive loads are applied to the hull or other parts of the vessel |
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Where possible, friction-enhancing materials should be laid beneath the cargo and between layers |
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Fill in any gaps between individual items of cargo |
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Protect cargo from chafing, scratching and similar mechanical damage |
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Protect cargo from harm caused by lashings and other securing materials |
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Heavy goods in particular, such as steel products, should where possible be stowed without gaps in a level layer from ship’s side to ship’s side |
 Figure 9 |
Railroad:
Wire rod must be transported in freight cars having a headboard and side walls (stanchions) with sufficient strength and loading capacity. Nonslip material must also be placed under the load and between layers. Gaps in the load are often unavoidable due to the handling methods used and freight car characteristics (load distribution), so the load must be secured in accordance with anticipated accelerations by direct securing (e.g. tight fit, loop lashing) and/or by frictional securing (e.g. tie-down lashing).
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Risk factors and loss prevention
RF Temperature
Wire rod does not have any particular ambient temperature requirements for transportation and storage. It should however be noted that the temperature of the wire determines whether the cargo sweats.
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RF Humidity/Moisture
Wire rod requires particular humidity/moisture and possibly ventilation conditions (SC VI) (storage climate conditions).
| Designation | Humidity/water content | Source |
| Relative humidity | <40 – 50% | [1] |
Steel is a cargo which is at risk of corrosion. Corrosion losses are in particular caused by
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Seawater and seasalt aerosols, | |
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during maritime transport due to leaky containers or hatches | |
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during storage at sea ports near water | |
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Rain water, | |
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when containers are damaged | |
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uncovered railroad freight cars and trucks | |
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incorrect storage in the open | |
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use of unsuitable tarpaulins | |
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exposed loading in wet weather conditions | |
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Condensation water, | |
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on the means of transport | |
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on the cargo/load | |
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within the packaging | |
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Accompanying chemical cargo, | |
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Residues of chemicals from previous cargoes, possibly combined with moisture, | |
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Hygroscopic accompanying cargo (e.g. fresh lumber) and | |
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Relative humidities > 40%. | |
Steel corrosion begins at a relative humidity of 40% and rapidly accelerates at relative humidities > 60%:
 Figure 10 |
A distinction may be drawn between various Types of corrosion.
There are two main causes of corrosion:
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Pure oxidation and |
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electrochemical decomposition of the metal due to the presence of an electrolyte (e.g. salts, acids, bases). |
Pure oxidation means combination of the ferrous metal with atmospheric oxygen. Oxidation is assisted by electrochemical (electrolytic) processes. The extent of electrolytic decomposition is determined by the conductivity of the electrolyte present. For example, salt water is more conductive than fresh water and therefore has a greater corrosive effect. The effect of sulfurous acid is even more extreme.
If corrosion damage is suspected, testing is performed using the silver nitrate method, to find out whether chloride solutions or fresh water are the cause. When determining the origin of the sea salt on the cargo surface (corrosion resulting from contact with seawater or spray deposition by the hold/container air), the damaged surface is assessed with a magnifying glass (30x magnification): cubic sodium chloride (NaCl) crystals of an edge length of approx. 1/5 mm indicate contact with seawater. In the case of spray deposition, no crystal structures may be observed, since the crystals are too small (1/100 mm).
In the case of hot-rolled steel, it is usual to store it in the open and to transport it without protection, such that no protection is provided against rain etc.. Such sheet therefore generally exhibits a layer of surface rust (rust film). Since the rust is removed from the steel (by pickling) prior to further processing, the quality of the steel is not impaired. Hot-rolled sheets must also be protected from chloride solutions (e.g. seawater or fertilizer), since pickling cannot remove uneven local corrosion or pitting corrosion. Especially in the case of damage by salt water, the wires should be rinsed off with fresh water as soon as possible after arrival with the receiver and then pickled because significant delay prior to pickling may have the above-stated consequences. In most cases, pickling is enough to remove any rust. However, only the surface rust (rust film), but neither uneven local corrosion nor pitting corrosion, is removed. For reasons of quality maintenance, the aim should always be to store, handle and transport the sheets in the dry.
Surface-treated wire is more sensitive to corrosion than hot-rolled wire, such that it is additionally packed, for example, in corrosion protection, fiber-reinforced packing or plastic-coated kraft paper (montan paper) and plastic films. It is therefore important to keep moisture away at all times; unprotected storage in the open or unprotected cargo handling in wet weather should be avoided.
 Figure 11 |
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RF Ventilation
Wire rod requires particular humidity/moisture and possibly ventilation conditions (SC VI) (storage climate conditions).
Steel corrosion accelerates rapidly at relative humidity > 60%. If possible, relative humidity should be reduced to below 60% by appropriate ventilation measures.
However, the following should be noted:
- Steel exhibits a lower temperature than the external temperature anticipated during transit:
If the temperature of the ambient air outside the ship rises, this has only a minimal effect on the temperature of the cargo. Ventilation with „warm“ external air may result in cargo sweat on the „cold“ steel, if the temperature of the latter is below the dew point of the ambient air. In such a case, ventilation may encourage corrosion.
- The steel is warmer than the external temperatures anticipated in transit:
Ventilation may be performed without any risk of cargo sweat formation. However, cooling of the ship’s sides may cause their temperature to drop below the dew point of the hold air, resulting in ship sweat inside the hold. In this case, the temperature of the hold air should be adjusted by ventilation to match that of the external air.
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RF Biotic activity
This risk factor has no significant influence on the transport of this product.
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RF Gases
Sulfur dioxides (exhaust gases from e.g. cargo handling equipment) have an extremely corrosion-promoting action on steel. It is therefore essential to prevent any contact with sulfur and its gases. Holds should accordingly be cleaned prior to loading.
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RF Self-heating / Spontaneous combustion
This risk factor has no significant influence on the transport of this product.
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RF Odor
This risk factor has no significant influence on the transport of this product.
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RF Contamination
| Active behavior | Wire does not normally cause contamination. Corrosion protection agents may, however, contaminate other cargo. |
| Passive behavior | Dust from coal, ores, salts and especially fertilizers and other bulk materials has a corrosive effect. For this reason, the holds have accordingly to be washed clean, to remove any residues from previous cargoes. When washing out ship holds with seawater, it must be borne in mind that seawater also contains salts which would encourage corrosion later in the voyage. It is therefore best to use fresh water for cleaning purposes. The product must also be protected from acids, aggressive gases (sulfur dioxide) and readily decomposing chemicals, as these also accelerate corrosion. |
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RF Mechanical influences
In order to avoid damage to pipes or their packaging by mechanical stresses, it is essential that stowing, cushioning, bracing, lashing and securing on the means of transport are performed carefully and in accordance with instructions. Suitable slinging and cargo handling equipment and lifting gear must be selected and used on the basis of the cargo’s weight and slinging points.
If the strapping (metal straps) is damaged or broken, the wire coils loosen and may result in tangled wire or other damage. Loosened wire coils result in problems during cargo handling and during subsequent unrolling prior to further processing.
Using wire ropes or chains for handling purposes may result in distortion to the edges of the coils.
 Figure 12 |
 Figure 13 |
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RF Toxicity / Hazards to health
This risk factor has no significant influence on the transport of this product.
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RF Shrinkage / Shortage / Theft
This risk factor has no significant influence on the transport of this product.
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RF Insect infestation
This risk factor has no significant influence on the transport of this product.
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