Fabrication Factors for Carbon Steel Pipe Vs. Stainless Steel PipeJuly 6, 2015
Carbon steel and stainless steel two extremely popular grades of pipe and useful materials for industrial pipe fabrications. Each type of material comes with its own particular sets of pros and cons and likewise each materials has different fabrication considerations. Let’s take a look at some of the main considerations.
Carbon Steel vs. Stainless SteelSince the invention of steel, metalworkers have produced different grades of steel depending on the application. This is done by varying the amount of carbon. Generally, steel recipes have a weight proportion of carbon in the 0.2% to 2.1% range. To enhance other properties of the base iron, mixtures may also include chromium, manganese, or Tungsten. Varying proportions of these elements produce steel with targeted values of ductility (the ability of a metal to be drawn into a wire), tensile strength (the ability to be stretched without breaking), and hardness. They can affect and control the thermal and electrical properties of the steel as well. The addition of these materials to the iron forms an alloy. The materials themselves serve to maintain the crystal lattice structure of the base iron atoms. Carbon steel depends mainly on carbon to form the durable alloy. Carbon steel may contain other agents such as manganese, cobalt, or tungsten, but the proportion of these materials is not specified. The following shows the four types of carbon steel:
- Mild / low – contain very low percentages of carbon
- Medium – 0.3 to 0.59% carbon by weight
- High – 0.6 to 0.99% carbon
- Ultra high – 1.0 to 2.0% carbon
Pipe Fabrication FactorsBoth carbon steel and stainless steel are used to produce components and structural parts for a wide range of purposes. When making a choice for a particular application, engineers must consider several factors:
- Tensile Strength and Weight – both carbon and stainless steel have a tensile strength and weight that are comparable. Their use in pipe fabrication depends partly on the method of the fabrication. When a pipe extruded, the ability to maintain specs depends on the ductility of the material, which is similar for both alloys. Pipe fittings are generally milled, and metalworkers can again expect similar results between the two materials. Often, designers who desire the ductility of steel with a lower weight consider aluminum. Like stainless steel, aluminum does not corrode.
- Reactivity – for applications requiring no reactivity, stainless steel is the clear choice. A noteworthy application is kitchen pots and pans. Carbon steel (and aluminum) reacts with food, producing flavor changes and potential health hazards. Stainless steel does not cause these interactions.
- Workability – both materials are easy to work in an array of fabrication methods, including hardening to create long-lasting components, machining without chipping or cracking, and welding to create durable joints.