Bloque 3. FOBIAS Y FILIAS: LA FORMACIÓN DE LOS IMAGINARIOS
2. Imaginarios en la formación de la idea de nación
steel, weather steel, and tool steel.
On board a ship we find this type of steel in hullplates, frames, deck plates, deck beams and bulkheads. A common composition of this type of steel is (%):
Steel can be generally classified as an alloy of Ferrum (Fe), better known as iron, and carbon (C). Iron is the main component in most types of steel. Steel is classified in three grades:
– Unalloyed steel (containing up to 1% alloy elements). This type of steel is also termed mild steel, carbon steel and carbon manganese steel.
– Low alloy steel (containing 1–5%
alloy elements).
– High alloy steel (containing more then 5% alloy elements).
Alloy elements are metals such as manganese (Mn), silicon (Si), chrome (Cr), nickel (Ni), molybdenum (Mo).
Carbon is not an alloy element.
Unalloyed steel
Often referred to as carbon steel, mild steel or black steel. On board a ship, unalloyed steel will usually be found in the superstructure.
Angle iron, flat iron and rod iron are usually in unalloyed steel. A common composition of this type of steel is as follows (%):
Use the following Unitor filler materials for welding unalloyed steel:
GPO, GPR, LH, LHV, MS, IMS, SPECIAL Low alloy steel
Low alloy steel includes construction steel, ship quality steel (sometimes referred to as high tensile steel), heat resistant steel, low temperature
Higher strength filler materials must be used for welding low alloy steel.
Use: SPECIAL, LH, LHV, LHT, LHL, LHR, ICROMO, TENSILE, GPS, HSTSF.
If there is doubt as to whether steel to be welded is unalloyed or low alloy, higher strength filler materials should always be used. They should always be used for welding the following components (including components in unalloyed steel): –Lifting equipment subject to heavy loads. Lifting lugs and other parts subject to sudden loads.
– Parts which are subject to heavy vibration (pipes, engine mountings, etc.)
– Welding deck equipment in position (winches, cranes, etc.).
– Welding cast steel (important). To differentiate between cast steel and cast iron, see the section on identification of metals.
Heat resistant steel Heat resistant steel is a low alloy steel, alloyed with a certain percentage of molybdenum (Mo) and sometimes also chromium (Cr). The addition of these alloying elements imparts heat resistant characteristics and the steel retains its strength at
Introduction
2.04
high temperatures. On board you will find this steel in boiler tubes, boiler plates and high pressure pipes.
A common composition is as follows (%):
For welding of heat resistant steel, filler material with heat resistant deposit only may be used. Selection
of the correct electrode for the job will depend on the percentage of Mo and Cr in the alloy. LHT and ICROMO are heat resistant filler materials in the Unitor range.
Steel types
Construction steel: St 37-4
High strength steel: St 5-70 Mangan steel: Mn-steel
Heat treated steel: CN 18, SCM
Hard wearing steel: SE 3 MS
SOLUTIONS: Unalloyed/low alloyed steel
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Low temperature steel
Low temperature steel containing nickel is today used more and more in processing equipment onboard ships carrying low temperature cargo.
We also find this type of steel in Ice – class hull plates.
The LHL electrode are a low temperature electrode for use on this type of steel.
Weathering steel
Weathering steel can be exposed to the weather without being painted.
Good corrosion resistance to seawater and flue gases. This type of steel contains Copper and Nickel.
Use LHR electrode for welding.
Fe C Mn Si
Main comp. 0.10 0.90 0.30
Mo Cr S P
0.50 1.00 0.03 0.03
Standard construction steel, high strength steel, manganese steel and hardwearing steel
Steel Tensile yield Elong- Hardness C Si Mn P S Cr Cu N Ni Mo
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SOLUTIONS: Unalloyed/low alloyed steel
Description Solution Examples
Joining of smaller diameter steel pipes (diameter less than 30 mm) where a capillary joint may be used.
Small diameter steel pipes (diameter up to 160 mm) with a wall thickness of up to 3 mm forming an I-butt joint or T-joint (flange to pipe).
Larger size steel pipes (over160 mm) with a wall thickness more than 3 mm forming an I-butt joint, V-butt joint or a T-joint.
Joining galvanized steel pipes forming a V-butt joint, rounded edges on the joint.
Thin plate galvanized steel constructions like air ducts and air channels.
AG-60-5
AG-45-53
MS-00 IMS-10
GPO-30N SPECIAL-303N MS-00
FC- BRONZE-61
BRONZE-64
FC-BRONZE-61
BRONZE-64
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SOLUTIONS: Unalloyed/low alloyed steel
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Description Solution Examples
Welding of thin sheet steel plate constructions as for example tanks and cover plates.
General purpose repair welding of unalloyed steel parts.
Fabrication of smaller steel parts like shelves, ladders and gangways in unalloyed steel.
Welding of clamps and brackets, and tack welding constructions before full welding.
Larger size
fabrication and repair jobs like welding of unalloyed steel bulkheads and deck in all positions.
GPO-30N/
SPECIAL-303N MS-00 IMS-10
GPO-30N SPECIAL-303N LH-314N LHV-316N
GPO-30N SPECIAL-303N LH-314N
GPO-30N SPECIAL-303N LH-314N
GPO-30N SPECIAL-303N LH-314N
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SOLUTIONS: Unalloyed/low alloyed steel
Description Solution Examples
For a rapid and large size weld build up in the downhand position on unalloyed steel/low alloyed steel constructions.
Welding repairs of low alloyed ship-building steel used in the hull, beams, deck, bulkheads, stiffeners, tanks, holds, hatch covers, frames etc.
Steel that takes vibration, strain and sudden loads.
Seawater, steam and cargo pipes made of low alloyed steel.
Deck and engine auxiliaries welded to deck or floor plates.
Welding on cranes and lifting equipment.
GPR-300H LHH-314H
SPECIAL-303N LH-314N LHV-316N
SPECIAL-303N LH-314N LHV-316N SPECIAL-303N LH-314N LHV-316N
SPECIAL-303N LH-314N LH-316N TENSILE-38N
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SOLUTIONS: Unalloyed/low alloyed steel
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Description Solution Examples
Boiler plates and tubes of heat resistant chromium molybdeniujm alloyed steel.
Welding subject to high loads (Lifting, lugs, etc.).
Cast steel repairs.
Weathering steel used for sea-water and flue gases.
Low temperature applications. Ice-class hull plates.
LHT-318N ICROMO-16
SPECIAL-303N LH-314N LHV-316N TENSILE-38N
LH-314N
LHR-30N
LHL-319N
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WELDING HANDBOOK NOTES
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