The standard specification for carbon steel forgings like ASTM A860 WHPY 52 covers the following topics: Normalized and tempered, Stress tests, Maximum weight, and elongation. It also covers the tensile, yield, and compressive strength of the material. The following are some examples of carbon steel forgings. They meet the minimum requirements for various applications. These requirements are used to produce forged components for piping systems. Forgings should be heat-treated according to the manufacturer’s specifications and meet or exceed the specified minimum carbon content.
Normalized
Typical uses of carbon steel forgings include general-purpose piping. The normalized carbon steel forging specification includes two classes, based on their mechanical properties. Among the two classes, flanges may be forged or hot-rolled. Return bends, elbows, and tees may be forged or hot-rolled, but must be protected against sudden cooling. To obtain the normalized carbon steel forging specification, you must use high-quality forged material.
The normalizing process produces a pearlite-like structure that is layered with two phases. This is a significant difference from annealing, which requires the metal to be heated and cooled slowly inside a furnace. As a result, normalized steel is harder and stronger than annealed steel. Another benefit of normalized carbon steel is that it is more economical than annealed steel. The rate at which the carbon steel cools during the normalizing process is largely dependent on the thickness of the piece. Thick pieces become more ductile.
While flanges do not typically require heat treatment, this is necessary for most items above 4″ NPS and Class 300. This process involves quenching the forged part to an austenite temperature of around 1550 F and cooling it in still air to room temperature. During the normalizing process, the flange or other forged part is allowed to remain over this temperature for one to two hours before it is returned to room temperature.
Normalizing is a process that imparts strength and hardness to carbon steel. By refining the grain structure, normalizing improves mechanical properties. The process reduces internal stresses, improves microstructural homogeneity, and improves thermal treatment response. Normalizing is typically used for parts that must be tough or withstand a significant amount of impact. And it helps reduce stress in the manufacturing process. It also helps prevent heat-treating problems.
Normalized and Tempered
When we think of heat-treating a metal, we often consider it from a microstructural and thermal processing standpoint. We can think of normalizing steel as the process that increases its hardness and toughness by heating it above its transformation range and cooling it in air below that point. In this article, we’ll discuss the normalizing of carbon steel, its uses, and how it differs from annealing and quenching. The following tables will provide information on typical normalizing temperatures for standard carbon steel.
Forgings can be specified in four ways: annealed, normalized, and tempered. These designations indicate the degree of heat treatment required to achieve the final physical and mechanical properties. These processes are not suitable for high-alloy steels, such as stainless steel, high-speed steels, or steels containing more than 3% chromium. In such cases, heat-treating steel would require a different process.
A tempering process involves cooling the steel at a specific rate, below its critical temperature, thereby improving its toughness and hardness. This process is similar to tempering but differs from it in many ways. While tempering improves toughness and machinability, it does not produce the same degree of hardness as quenching or normalizing. The most important difference between the two is the precipitation of intermetallic phases during the cooling process.
A normalized and tempered carbon steel forging may have a high degree of toughness compared to wrought steel of the same thickness. Normalized steels may exhibit some higher levels of toughness than wrought steels, and may even be less resistant to bending. But if you’re looking for tough steel, you should opt for tempered carbon steel. And this will be the best choice for the average person.
Stress Tests
Stress tests for carbon steel forgings are required by certain standards. They are carried out to determine the strength of forgings and determine their strength against fracture. During the tests, carbon steel forgings are tested by applying a tangential magnetic field to the surface of the forgings. The amount of stress-induced on the forgings depends on the thickness of the forgings. These stresses are considered to be normal.
The results of stress tests for carbon steel forgings are critical in materials engineering. Failure of a forging results from the propagation of cracks below its yield strength. The crack growth law is the same as the Coffin-Manson high-strain, low-cycle fatigue law. A study was conducted to determine the effect of previous fatigue history on the growth rate of a small crack. To this end, small holes were made with varying diameters to study the growth rate of cracks.
When the forgings are finished with hot working operations, they must be heat-treated to refine the grain structure and obtain the mechanical properties required. The tempering temperature must be at least 550degC, but lower temperatures are permissible if gearing is required. The set of tests must contain one tensile test specimen and three Charpy V-notch impact test specimens. Forgings are tempered when the tempering temperature is at least 550degC.
The test material must have a cross-sectional area similar to the cross-section of the forging. Alternatively, it can be separately forged. The test material must be machined to a diameter of 60mm or D/4. The final diameter of the toothed portion of the forging should be at least 60mm. However, the test material must be fabricated with the same reduction ratio as the forging.
Maximum Weight Limit
Forgings made of carbon steel are used for general-purpose piping. These forgings are divided into two classes based on their mechanical properties. Flanges may be made of a hot-rolled bar or forged. Elbows, return bends, tees, and other components made of bar stock are prohibited. They should be protected from sudden cooling. The maximum weight limit for carbon steel forgings is 4540 kg.
Forgings made of carbon steel contain a minimum of 0.35 percent carbon and a maximum of 1.35 percent manganese content. They are tensile and hardness tested to determine their strength and ductility. They are forged from specimens cut from heat-treated samples. Each heat-treated component must undergo a tension test. These tests determine whether the carbon steel forging is suited for the application.
Heat Treatment
The requirements for heat treatment of carbon steel forgings are set in the Heat Treatment Standard Specification for Carbon Steel Forgings. In accordance with this standard, the mechanical properties of the material must be in compliance with the required values for tensile strength, yield strength, elongation, and reduction of area. As an added benefit, this standard specifies the requirements for surface treatment and annealing.
The specification covers carbon and alloy steel forgings. The steel shall be melted and processed according to the chemical composition requirements. It shall undergo testing and quenching to meet the required hardness and tensile properties. This process is called hot-worked forging. The following procedures are included in the Heat Treatment Standard Specification for Carbon Steel Forgings:
The ASTM A266 Heat Treatment Standard for Carbon Steel Forgings covers four grades of forgings. Grades 1 and 2 are designated by their UNS number. They are also ordered as per their specifications or the standard specifications of the purchaser. They can be ordered as tube sheets, hubbed flat heads, or ASME Boiler and Pressure Vessel Code. When ordering forgings that meet this standard, make sure to ask for them to be heat-treated.
ASTM A266 carbon steel forgings are forged between two thousand and one thousand Fahrenheit, followed by quenching, tempering, and normalizing. Depending on the complexity of the part to be forged, actual hot forging temperatures may vary. The correct forging temperature is only determined in the early stages of the process. A higher temperature will likely result in surface defects and a lower temperature will prevent plastic deformation of C1045 carbon steel.
