However, for complex shapes, flame cutting or plasma jet cutting may be used as well. The most common methods are mechanical methods, such as cutting with guillotine knives, circular knives, high-speed blades or punching with dies. Once the steel is worked and ready, the batch is cut to fit order requirements. This is followed by repeated annealing phases until achieving the desired properties. Removing this scale is essential to creating the oxide barrier that gives stainless it’s characteristic corrosion and stain resistance.ĭescaling or pickling removes this scale using either acid baths (known as acid pickling) or through controlled heating and cooling in an oxygen free environment.ĭepending on the final product, the metal might return to rolling or extruding for further processing. It can also impact the stain-resistance, durability and weldability of the steel. This accumulation isn’t simply unattractive. Descaling or PicklingĪs steel is worked through the various steps, it often accumulates scale on the surface. The exact temperatures and times involved will depend on the grade of steel, with both heating and cooling rates impacting the final product. These cycles help to soften steel and relieve internal stress. This involves controlled heating and cooling cycles. AnnealingĪfter rolling, most steel undergoes an annealing process. However, it can also deform the steel’s structure and often requires heat treatment to recrystallize the steel to its original microstructure. This process creates a more attractive, uniform finish. Multiple supported rollers are used to shape the steel. Often used when precision is required, cold rolling occurs below the recrystallization temperature of the steel. In most cases, this will involve rolling through multiple mills over time to achieve the desired thickness. The process uses repeated passes to adjust the dimensions of the steel slowly. Precise temperature control throughout the process keeps the steel soft enough to work without altering the structure. Performed at temperatures higher than the recrystallization temperature of the steel, this step helps to set the rough physical dimensions of the steel. Blooms and billets become bars and wires.ĭepending on the grade or format ordered, a steel might go through some of these steps multiple times to create the desired appearance or characteristics. The exact shape and dimensions will depend on the final product.įorms are then marked with an identifier to track the batch through the various processes to follow.įrom here steps will differ depending on the intended grade and final product or function. With the molten steel created, the foundry must now create the primitive shape used to cool and work the steel. Adjustments are then made until the mixture meets the required standard. This ensures that the metal meets requirements for its intended grade and that the steel’s composition is consistent throughout the batch. Step 3: TuningĪfter reducing carbon, a final balancing and homogenization of temperature and chemistry occurs. A vacuum then removes vented gases from the chamber, further reducing carbon content.īoth methods offer precise control of carbon content to ensure a proper mixture and exact characteristics in the final stainless steel product. In this method, molten steel is transferred to another chamber where oxygen is injected into the steel while heat is applied. The other method used is Vacuum Oxygen Decarburization (VOD). Injecting an argon gas mixture into the molten steel reduces carbon content with minimal loss of other essential elements. The first is through Argon Oxygen Decarburization (AOD). There are two ways foundries control carbon content. However, too much carbon can create problems-such as carbide precipitation during welding.īefore casting molten stainless steel, calibration and reduction of carbon content to the proper level is essential. Step 2: Removing Carbon ContentĬarbon helps to increase the hardness and strength of iron. This helps to not only control costs but reduce environmental impact.Įxact temperatures will vary based on the grade of steel created. Using high-power electrodes, the EAF heats the metals over the course of many hours to create a molten, fluid mixture.Īs stainless steel is 100% recyclable, many stainless orders contain as much as 60% recycled steel. Manufacturing stainless steel starts with melting scrap metals and additives in an electric arc furnace (EAF). How a grade of steel is shaped, worked and finished plays a significant role in determining how it looks and performs.īefore you can create a deliverable steel product, you must first create the molten alloy.īecause of this most steel grades share common starting steps. The exact process for a grade of stainless steel will differ in the later stages.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |