WHAT IS METALWORKING OPERATIONS ?
When it comes to production and manufacturing, it may be viewed from a broader perspective. However, when it comes to manufacturing involving metals such as the steel plant, foundry, automobile plants, and military weapons productions, etc. the metalworking process cannot be eluded from the whole process.
Generally, metalworking is the foundational knowledge behind modern metal manufacturing and processing practices. It is obvious that some individuals may still find it confusing when it comes to defining metalworking and relating it to mod4ern industrial practices.
Based on its previous understanding, metalworking is the process of working with metals to create individual parts, assemblies, or large-scale structures. The term covers a wide range of work from large ships and bridges to precise engine parts and delicate jewelry. Based on the term, it includes a correspondingly wide range of metal skills, processes, and tools.
Metalworking is a science, art, hobby, industry, and trade. Its historical roots span cultures, civilizations, and millennia. Metalworking has evolved from the discovery of smelting various ores, producing malleable and ductile metal useful tools and adornments.
Metalworking processes remain the bed of modern metal processing methods. Industrial operations such as metal forming, cutting, or joining processes, etc. involve the basic knowledge of metalworking. Even modern small machine shops have a number of special machine tool capable of creating a precise useful workpiece through simple metal handling operations such as shearing, bending, and drilling operations.
Generally, metalworking can be classified into three major operations such as; forming, cutting and joining operations. Each of the categories contains various processes. Prior to most operations, the metal must be marked out and/or measured, depending on the desired finished product.
Therefore, in primitive metalworking process marking is very essential before the proper working on the metal can be carried out. Making can be in the form of punching, drawing with chalk, marking with dividers, etc. modern metalworking processes have gone beyond just making, rather machine operation simulation can be used to ascertain the operation of the machine on the workpiece.
Marking out a workpiece is a laying out procedure for any metal fabrication and construction processes such as the making of fence-gates, metal doors, window protectors, etc.
In terms of definition, marking out is a process of transferring a design or pattern to a workpiece and is the first step in the handcraft of metalworking. It is performed in many industries or hobbies, although in industry, the repetition eliminates the need to mark out every individual piece.
In the metal trades area, marking out consists of transferring the engineer’s plan to the workpiece in preparation for the next step, machining or manufacture.
Calipers are hand tools designed to precisely measure the distance between two points. Most calipers have two sets of flat, parallel edges used for inner or outer diameter measurements.
These calipers can be accurate to within one-thousand of an inch. Different types of calipers have different mechanisms for displaying the distance measured. In the case where larger objects need to be measured with less precision, a tape measure is often used.
METAL FORMING OPERATIONS
Among the classes of metalworking operations, forming is the most stressful and capital intensive operation because it could be from ordinary metal forging operation to the rolling operation, and most of all smelting or casting operations.
No matter the intended operation all of the above will require a high level of heat treatment. Metals can easily be worked upon when their temperature is above the crystallization temperature.
While casting achieves a specific form by pouring molten metal into a mold and allowing it to cool, with no mechanical force.
Most forms of casting include:
• Investment casting i.e. lost wax casting
• Centrifugal casting
• Die casting
• Sand casting
• Shell casting
• Spin casting
The forming process modifies metal or workpiece by deforming the object, that is, without removing any material. Forming is done with a system of mechanical forces and especially for bulk metal forming, with heat.
The common forming process is bulk-forming. It is a plastic deformation which involves using heat or pressure to make workpieces more conducive to mechanical force. Previously the process can be carried out by blacksmith alongside casting operations.
However, both operations have become major operations in modern manufacturing industries. Modern industrial operations involving bulk-forming include; cold sizing, extrusion, drawing, forging, powder metallurgy, friction drilling, rolling, and burnishing.
Sheet or tube forming operations
It is another metal forming process where metal is mechanically forced to sheet or tube shape at room temperature. Modern processes could have the addition of heat to the dies and /or parts. The advancement of the operation has made progressive die stamping possible through automated metalworking technology.
The innovation is a method that can encompass punching, coining, bending and several other ways that modify metal size/shape at less cost while resulting in less scrap.
Other processes under this operation are; decambering, deep drawing, flow forming, hydroforming, hot metal gas forming, hot press hardening, incremental forming, spinning, shear forming, raising, roll forming, roll bending, repousse and chasing, rubber pad forming, shearing, superplastic forming, and wheeling.
METAL CUTTING OPERATIONS
Among the metalworking operations, cutting is a where metal is brought to a specific geometry by removing excess material using various kinds of tooling to leave a finished part that meets specifications.
Two products can be found at the net result of cutting operation, they are the waste or excess material and the finished part. The waste metals could be in the form of chips or swarf.
Cutting operation has many categories which include;
Chip producing processes mostly known as machining. Example; drilling, milling, turning, grinding, and filing, etc.
Burning a set of processes wherein the metal is cut by oxidizing a kerf to separate pieces of metal.
Miscellaneous specialty process, not falling easily into either of the above categories.
METAL WELDING OPERATIONS
Metal Welding is among the metalworking operations. It is used during metal fabrication and construction process for the purpose of joining two metals together. It is a popular and generally accepted method of joining metals of various kinds together. The strength of the welded joint determines the overall structural integrity of the fabricated parts.
Weak joints mean weak parts and vice versa. During welding the ends of the two workpieces intended to be joined together are melted with the heat from electrode arc, the electrode then deposits its molten parts to the gap that exist between the two heated workpieces end causing rapid fusion of the entire metals from the electrode to the heated ends of the workpieces.
Welding can be done using any energy sources besides the arc welding process explained above.
Some of the energy sources are gas flame, a laser, an electron beam, friction, and ultrasound, etc. in the industry, welding operation can be carried out in any location not exposed to flammable substance such as gas filling stations, petrol or gas flowline areas, etc. where it is mandatory, the necessary safety procedures will be followed.
Some welding operations can be done underwater, in space, and in the open air with unfavorable conditions.
Welding could cause burns, dehydration, electric shock, inhaling of poisonous fumes, and overexposure to ultraviolet light, among other hazards associated with the operation.
Other metalworking operations are Brazing, soldering, and riveting.
However, their application is for lighter structures that wouldn’t be subjected to severe workloads. Examples; portable houses, roofing, electronic dashboards, and jewelry, etc.
