For any successful operation, it is important to do the math right. In welding, calculating consumable consumption is an important part to understand the TCI and plan out the budget accordingly. It also helps to understand the increasing prices and set the cost of welding service right.
The three main parameters to estimate the cost of welding are -
Consumption of electrode or filler to calculate the cost of consumption
Arc time to calculate welder’s hour cost
Cost of electricity used
What are Consumables?
Filler materials, also known as consumables, are used in welding. These compounds, as their names suggest, provide a filler or molten body that allows a strong link to be created between the base metals employed. Most welding methods will also necessitate some type of shielding to prevent oxidation of both the main components and the filler.
The parent material refers to the metal parts that are welded together. Consumables are the materials that have been introduced to aid in the formation of this joint. These materials may be referred to as parent plate or pipe, filler wire, consumable electrode (for arc welding), and so on, depending on their shape.
What are the Types of Consumables in welding?
There are different types of consumables used in welding processes. The most common consumables are -
Stick Electrode/ Rod Electrode - Stick welding calls for a lot of expertise as well as familiarity with stick electrodes (also called welding rods). According to the American Welding Society, there are various stick electrode types, some of which are the E6010, E6011, E6012, E6013, E7014, E7024, and E7018 electrodes.
Fluxes - To stop the hot metals from oxidizing, flux is frequently employed to create a shield of gas around the weld pool. Flux normally functions as a deoxidizer to stop porosity from developing in the weld pool. Welding consumables are defined as flux and filler metals. The flux burns when an arc is struck, igniting a sequence of intricate chemical processes. To shelter the molten weld pool from ambient contaminants, shielding gas is released as the flux components burn in the welding arc.
Solid Wires - This provides deep penetration in the root and usually has little spatter.
Saw Wires - These are consumables that produce exceptional productivity when combined with flux. It is crucial to consider how the wire, flux, and the metals to be welded will work together during the welding process. SAW wires are made to preserve good mechanical qualities after extended post-weld heat treatment, unlike other wires that are less durable.
Flux Code Wires - External shielding gas is required for gas-shielded flux-cored wires. The flux layer on gas-shielded flux-cored wires solidifies faster than the molten weld material. As a result, when welding overhead or vertically up, it generates a ledge to hold the molten pool.
What is consumable consumption?
The calculation of the fillers required in the welding process like electrodes required in the welding process is called consumable consumption. In the welding process, two pieces of metals are joined together with excessive heat. In this process, electrodes or gasses are used to make the metallic bond strong enough for practical use.
How to Calculate Consumable Consumption?
To know how to calculate the cost of consumption, one should know the metal and the filler well. You can calculate the consumable consumption by the following formula -
W = A x ρ x L x 1 / E
W = Weight of consumables in grams,
A = cross sectional area,
ρ = Density ( gm/cm3),
L = Length in cm,
E = Deposition efficiency
Here is how you calculate crossectional area -
One important thing you need to know correctly is the density of the metal. To know the density of common metals, refer to the following list -
Carbon Steel - 7.8
Magnesium - 1.7
Granite - 2.6-2.7
Diamond - 3.5
Steel - 7.8
Iron - 7.8
Brass - 8.6
Copper - 8.3-9.0
Lead - 11.3
Mercury - 13.6
Uranium - 18.7
Gold - 19.3
Platinum - 21.4
Iridium - 22.4
What things to consider while choosing consumables for welding?
Choosing consumables in welding is a very crucial part of the process. A wrong consumable can lower the quality of welds significantly and can cal for re-work. You should look for the following factors while choosing consumables for your welding -
What is the weld exposed to during its lifetime? (Includes force, pressure, load, temperature, and environmental conditions)
What are the mechanical and chemical requirements?
What is the applicable welding process?
What is the welding position with its progression?
What type of consumable?
Another way how welders choose their consumables is by the type of welding process. By type following consumables suit the different processes of welding -
Electrodes for SMAW,
Solid welding wire for TIG(GTAW), MIG/MAG (GMAW) and SAW,
Flux-cored welding wire for MIG/MAG (FCAW) and SAW,
Flux powders for SAW.
There are densities in generalized conditions. Increasing pressure increases the density of the material while increasing temperature decreases the density of the material.
The deposition efficiency of different welding processes is -
SMAW - 50 - 55
GTAW - 90 - 96
SAW - 96 - 98
FCAW-S - 72 - 78
GMAW - 96 - 98
How Consumables can affect welding quality?
To identify which angles offer the best connection and electrical conductivity, thorough study and engineering are required to produce high-quality consumables. A lower level of research and design is often behind lower-quality consumables, which might result in contact tips and gas diffusers that do not fit together properly and produce electrical resistance. This problem may result in subpar quality and early consumable failure.
For an efficient welding company, it is important to understand the effect of consumables on welding. These costs can sometimes look smaller but have a great impact on the overall budget of the organization. So, it is important to calculate the cost of welding correctly.