A Brief Introduction to Plain Steel
Steel is one of the things that have completely changed the world. It changed virtually everything from transportation to construction. Equipment and machines made using steel are used in every single industry. There are different forms of steel for industrial construction. The most common are:
- Plain Carbon Steel
- Rebar Steel
- Structural Steel
In this article, we will cover plain carbon steel. If you work in the job shop, you are already familiar with the term plain steel. So, what is that? It is mild steel. Before you choose a material, you need to do a lot of studies to determine if the material has physical and chemical properties that make it suitable for the job. There are several important specifications you must consider. Engineers establish end-user requirements. You can achieve the desired results if the material has the properties to meet those requirements.
Plain steel or mild steel refers to SAE 1020 or ASTM A36/ASME SA36. The alloy content is relatively low in these materials. Noncritical structural fabrications require these materials. You can get A36/SA36 in different shapes such as round bars, flat bars, angles, channels, beams and plates.
Consider the following important factors when choosing a material for an end-use:
- Corrosion resistance
- Hardness, hardenability
- Wear resistance
- Surface condition
- Shape (channel, T, angle, beam, plate etc)
- Length, width and thickness
- Test requirements
A36/SA36 comes with a moderate tensile and yield strength. Its tensile strength is between 58,000 PSI to 80,000 PSI and the yield is 36,000 PSI. The tensile strength depends on silicon, manganese and carbon content. It also depends on the thickness. Production methods also affect the material’s tensile strength. These methods include hot or cold, rolling or extruding. Adding manganese and carbon increases strength but at the cost of ductility.
Corrosion and Wear Resistance
Avoid A36/SA36 if you want corrosion resistance. The hardness and hardenability of the material determine its wear resistance.
A36/SA36 is not a good choice if you want corrosion resistance. It does not contain nickel, chromium or copper.
Ductility and Formability
There is a direct link between formability and ductility. You need to test for reduction, elongation, yield and tensile to determine these properties. Use A36/SA36 for ductility and formability. It is easy to roll it. The best thing is that it does not springback.
You can also get relatively new ASTM A36 material-related specifications. These specifications include ASTM A1018 Grade 36 and ASTM A1011 Grade 36. Adding steel increases strength and hardenability. Work hardening requires Manganese. Increasing tensile strength also requires work hardening. You can increase hardenability with phosphorus but this element is not beneficial. If it is over 0.04%, this may cause embrittlement. Sulfur enhances machinability but when it comes to welding, it can be detrimental. Adding silicon also increases hardenability. The atmospheric resistance of some low-carbon steels is increased by adding copper.
Whether you are using plain steel or some other forms of steel for industrial construction, you must do proper research to ensure that the material is the best for end use.