1. Introduction
Choosing the right material in the production of metal products is a key factor determining the durability, reliability, and safety of the final product. Every product, whether a structural component, equipment housing, or architectural element, is subject to various operational loads, environmental influences, and chemical factors.
The service life of a product, its resistance to deformation, corrosion, and temperature fluctuations, directly depends on the material. An incorrect choice can lead to accelerated wear, failure, or emergency situations.
When selecting a material, it is necessary to consider a range of factors, the main ones being:
- mechanical loads;
- exposure to moisture and corrosion risks;
- temperature fluctuations;
- operating conditions (indoor or outdoor);
- weight, aesthetic, and cost requirements.
Proper material selection is the foundation for the safe and efficient production of metal products, minimizing defects, and ensuring operational reliability.
2. Why is material selection critical in metal product manufacturing?
The impact of the external environment manifests itself gradually but inevitably. Corrosion reduces wall thickness, and therefore load-bearing capacity. If a sheet thickness is 5 mm and after 10 years of use decreases to 4 mm, the cross-sectional area has decreased by 20%, which increases the working stress by the same amount.
Mechanical loads include a constant component (self-weight) and a variable component (wind, vibration, snow). In areas with high snow loads, it can reach 240 kg/m². This must be taken into account when selecting the type of metal and its thickness.
During the design and engineering of products, it is important to consider:
- tension and compression;
- bending;
- torsion;
- impact loads, etc.
It is also important to consider temperature fluctuations, as they affect the structure of the metal. When heated, the metal expands, and when cooled, it contracts. This is important to consider when designing products operating in temperatures ranging from -50 to +200°C.
3. Main Materials Used in the Manufacture of Metal Products
3.1 Carbon Steel
This is the most common material used in the manufacture of metal products. Its yield strength is 235-355 MPa, and its density is approximately 7850 kg/m³. It is characterized by high strength and affordability.
However, the corrosion resistance of this material is low. Without a coating, the corrosion rate in a humid environment can reach 0.2 mm per year. Therefore, additional protective treatment is required for long-term service.
3.2 Stainless Steel
A chromium content of over 10.5% forms a passive oxide film, which provides corrosion resistance. The yield strength varies from 200 to 600 MPa, depending on the steel grade.
Therefore, stainless steel is widely used in the food and chemical industries, where sanitary safety and resistance to aggressive environments are critical.
3.3 Galvanized Steel
A zinc coating 40-200 µm thick reliably protects steel from corrosion, creating a barrier against external influences. The average service life of galvanized products outdoors is 15-30 years, depending on the climate zone.
This type of material is a compromise between cost and durability.
3.4 Aluminum and Alloys
The density of aluminum is only 2700 kg/m³, which is almost 3 times less than that of steel. The yield strength of common alloys reaches 120-300 MPa.
Aluminum is resistant to moisture thanks to a natural oxide film that protects the metal from corrosion. However, its modulus of elasticity (E ≈ 70 GPa) is significantly lower than that of steel (E ≈ 210 GPa), so under the same load, the deflection of aluminum structures will be 3 times greater.
4. Technological Features of Material Processing
The selection of material for metal structures must consider not only mechanical properties but also the technological features of the upcoming operations. Laser cutting of aluminum requires power adjustments due to its high reflectivity, welding stainless steel requires a strict temperature regime (no higher than 1500°C), and bending requires a minimum bending radius (1-1.5 times the sheet thickness for steel). Incorrect material selection leads to cracks, deformations, or reduced weld strength.
Modern technologies make it possible to determine the suitability of a material for production in advance. CNC machines ensure repeatability with tolerances of ±0.1 mm, ultrasonic testing measures coating thickness and identifies defects, and load tests (with a 10-20% safety margin) confirm the calculated strength. A comprehensive approach—from property analysis to process trial processing—guarantees the quality of serial production.
5. Mistakes in Selecting Materials for Manufacture of Metal Products
The first mistake to note is unreasonable cost-cutting.
In practice, situations often arise where, with a design thickness of 6 mm, a 5 mm sheet is used to save money. This reduces the load-bearing capacity by approximately 17%.
The second mistake is ignoring operating conditions. Galvanizing deteriorates in aggressive chemical environments, structural steel rusts in moisture, and aluminum cannot withstand high loads due to its low modulus of elasticity. Ignoring climatic conditions also applies, leading to accelerated corrosion. The absence of a protective coating in 85% humidity conditions reduces the service life by 2-3 times.
Failure to comply with GOST and technical requirements can lead to rejection of the project and additional costs. Furthermore, failure to verify certificates leads to hidden structural defects, which manifest themselves in increased defects during processing or premature failure of the finished product during operation.
6. Conclusion
The production of metal products is a complex of engineering solutions in which the material determines the strength, stability, and service life of the structure. A sound choice is based on stress calculations, temperature analysis, and assessment of the corrosive environment. Metal manufacturing does not allow for a shortcut: only professional calculations, compliance with regulations, and quality control ensure reliability and safety. The right material is the foundation of a durable and efficient metal structure.
