Cold Rolled High Carbon Steel Spring Steel Strip
Cold rolled high carbon steel spring steel strip combines ease of fabrication with good strength and surface finish. It is valued for its strength properties and operates at significantly higher levels of tensile strength/hardness than mild steel grades.
These metals can also be made into a variety of different shapes such as shims. The shims are used as spacers between components.
Tensile Strength
Whether you’re designing a steel spring or other metal components for an industrial application, the tensile strength of your strip is an important factor to consider. This is how much force it can resist before breaking, and the higher this number is, the more it will be able to bear a load. The ductility of your strip is also an important characteristic to look at because it can provide insight into how easy it will be for you to form it.
High carbon steel spring steel strip can be produced to a range of tensile strengths/hardnesses depending on your final component-manufacturing processes and end-use applications. It is typically available in the annealed condition where hardness levels can range from 160 – 200 VPN (equivalent to tensile strengths up to 690 N/mm2) or in the pre-hardened and tempered conditions where hardnesses can be up to 650 VPN.
HSLA strip, or high strength low alloy strip, offers an excellent balance of both strength and ductility, which makes it ideal for stamping and roll forming applications. After hot rolling, it goes through a cold reduction process on either a single stand cold roll mill or a tandem mill, then is reduced to the required thickness through cold slitting. It can be delivered in the annealed or the pre-hardened and tempered condition, and may be passivated for improved corrosion resistance.
Hardness
Alloyed carbon steels like spring steel can be produced with varying amounts of elements like chromium, cobalt, molybdenum, nickel, manganese, tungsten, vanadium and others to improve the steel’s properties like ductility, corrosion resistance, hardness and toughness. Typically, these metals are added to the high carbon steel during melting and refining to create different types of steel alloys that have particular property combinations.
Alloy steels can be used in place of high carbon spring steel when a project’s requirements aren’t as strict Cold rolled high carbon steel spring steel strip since they’re cheaper to produce. They’re not as suited for extreme temperatures or shock/ impact loads though.
Typical high carbon steels can be supplied in a softened/annealed condition or, alternatively, tempered to specific tensile strength/hardness levels to match the subsequent component-manufacturing processes and end-uses involved. For instance, a full-hard temper of 380 – 580 VPN is commonly used for room temperature springs. When these steels are tempered to higher hardness levels they can still retain good ductility even without stress relieving.
During the tempering process, the cold rolled strip is heated uniformly in an induction heater to the desired hardening temperature. Then, it’s quenched rapidly to achieve the final hardness and spring characteristics required for a given application. Quenching is usually done in oil but can also be performed using other liquids or polymer solutions depending on the type of steel being tempered.
Corrosion Resistance
There are several different types of steel spring strip available on the market. Some are metal alloys, such as music wire or chrome silicon, that provide high strength and durability at Tinplate Sheet supplier an affordable price. Other alloys, like stainless steel, have added corrosion resistance properties. Spring strip can also be tempered to increase its strength. The steel can then undergo surface finishing, which enhances its look and improves the material’s durability.
The tensile strength and hardness of the spring steel can be adjusted to fit specific end-uses through various heat treatments and manufacturing processes. Cold coiling, for example, results in higher tensile strengths but lower ductility, while hot coiling has the opposite effect. The steel can also be tempered to increase its strength after it is quenched, which can significantly improve its fatigue and endurance strength.
Stainless steel spring strip, such as type 420 or ASTM A313 (18 percent chromium and 8 percent nickel), exhibits excellent strength, fatigue, and endurance under conditions that can generate high stresses. It is available in diameters from 0.031 to 0.500 inch, with some larger sizes, and can be either annealed or pre-tempered. Surface finishing is a final step that removes any rust and other contaminants, and can be used for cosmetic enhancement or rust prevention purposes. Other finishes include shot peening, which involves impacting the strip with ceramic, glass, or metallic particles to increase its durability.
Finish
High carbon spring steel can be finished in a variety of ways, making it an excellent choice for manufacturers that need sturdy, pliable metal. It can be rolled into flat sheets, coiled into wire, or forged into intricate parts like lock picks, woodworking band saw blades, tool handles, and even vehicle coil springs. It can also be used to make hammers, scissors, pliers, and any other type of tool that requires a combination of strength and flexibility.
The process of tempering enables the alloy to be used in applications that require the steel to bend and twist repeatedly without being damaged. This is why it’s commonly used in door hinges and drawer slides, as well as machinery parts. The steel is typically tempered to a hardness between Rockwell C 42 and 60, or between RC 54 and 57 for the higher hardness versions.
Spring steel strip is manufactured from a hot rolled coil that has been pickled and then reduced by a single stand cold roll mill in either a straight away or reversing mill, or a tandem mill consisting of multiple single stands. The product is then slit to the desired width through the process of roll slitting. The slitted strip is then ready for use.
