ASTM A193M-1998a Alloy steel and stainless steel bolting materials for high temperature service

ASTM A193M-1998a Specification for Alloy Steel and Stainless Steel Bolting Materials for High Temperature Service

ASTM A193M-1998a is a material specification developed by the American Society for Testing and Materials (ASTM). It specifies the requirements for alloy steel and stainless steel bolting materials for high temperature service. The scope of the specification covers round, square and hexagon shape bolts and screws with diameters of 0.25 in. up to 4 in., as well as studs and stud bolts of any diameter. ASTM A193M-1998a covers material grades F1, F5, F9, F11, F22, and F91. All of these grades are used for components in high temperature service conditions.

ASTM A193M-1998a defines a number of requirements for alloy steel and stainless steel bolting materials for high temperature service. It includes requirements for maximum tensile strength, yield strength, elongation, hardness, impact resistance and Charpy V-notch impact test values. It also defines requirements for the nonmetallic inclusions in the material, which must be below a specific size.

ASTM A193M-1998a also provides guidelines for several metal properties, such as ultimate tensile strength, yield strength, elongation, impact resistance and hardness. Additionally, it provides requirements for metal grain size and ductility, which must meet certain criteria.

ASTM A193M-1998a also provides requirements for other characteristics that can affect the performance of the bolting materials in the high temperature environment. These include the thermal effect on the material, surface finish, chemical composition, and dimensional tolerances. These requirements are designed to ensure the safety and reliability of the products in service.

In addition to its general requirements, ASTM A193M-1998a also provides additional requirements for special service conditions. For example, specific procedures must be established for stress relieving, heat treatment, aging treatment, and welding for application in high temperatures. Finally, it includes various nondestructive test methods for evaluating the quality of the bolting materials before and after their use.

Overall, ASTM A193M-1998a is an extremely comprehensive material standard for the production of alloy steel and stainless steel bolting materials for high temperature service. The standard includes various requirements for the chemical, mechanical, and nondestructive performance of the materials. It also has specific conditions for heat treatment and welding, as well as additional requirements for special service conditions. The guideline is designed to provide the highest degree of safety and reliability that bolting materials need to provide in a high temperature environment.

ASTM A193M-1998a is a specification for high temperature alloy steel and stainless steel bolts. It covers the chemical, mechanical, and dimensional requirements for three classes of bolted connections: Class 1, which covers high strength bolts used in pressure vessels, Class 2 which covers bolts requiring fracture-proof strength at temperatures up to 1000°F, and Class 3 which covers bolts requiring fracture-proof strength at temperatures to 1500°F. The bolts in this specification have various types of threads such as U-bolts and carriage bolts.

The high temperature alloy steel bolts specified by ASTM A193M-1998a are made of chromium-molybdenum steel, which is vacuum split-quad melted for the highest level of purity and mechanical properties. The alloy steel is heat treated to provide a high ultimate strength which may include: quench and tempering to meet maximum tensile strength requirements, stress relieving to reduce residual stresses, and normalizing to improve physical properties. The steel is then treated with zinc and silicon electroplating to protect it from corrosion.

The stainless steel bolts specified by ASTM A193M-1998a are made of austenitic stainless steel, which is vacuum melted for the highest level of purity and mechanical properties. These bolts are heat treated to provide enhanced corrosion resistance and mechanical properties. The heat treatment process includes annealing and quenching followed by tempering. The bolts are then treated with cadmium and iron plating to provide additional corrosion protection.

In addition to the chemical, mechanical, and dimensional requirements, ASTM A193M-1998a requires that the bolts be inspected for surface quality and dimension consistency. The surface of the bolts must be free from any blemishes, scratches, and nicks and the dimensions must meet the specified requirements. The bolts must also be tested for various quality control procedures including hardness testing, magnetic particle inspection, and radiographic processing.

ASTM A193M-1998a specifies the requirements for high temperature alloy steel and stainless steel bolts and provides assurance that these bolts will meet the most rigorous service conditions. The stringent requirements for quality and performance make these bolts a reliable choice for high temperature applications.