A-437 Alloy-Steel Turbine-Type Bolting Material Specially Heat Treated for High-Temperature Service

Description

This specifications covers alloy-steel bolting material specially heat treated for high-temperature service, such as steam turbine, gas turbine, and similar uses. The grades of steels covered here are: Grade B4B, Grade B4C, and Grade B4D. Steels of Grades B4B and B4C shall undergo heating, liquid quenching, reheating, tempering, and air or furnace cooling, respectively. Steels of Grade B4D shall undergo heating, oil quenching, reheating or tempering, and air of furnace cooling, respectively. Heat and product analyses shall be performed wherein specimens shall conform to required chemical composition of carbon, manganese, phosphorus, sulfur, silicon, nickel, chromium, molybdenum, vanadium, tungsten, aluminum, titanium, and tin. The steels shall undergo tensile, impact, and hardness tests, and shall conform to the following mechanical requirements: tensile strength, yield strength, elongation, impact value, Brinell hardness number, and Rockwell hardness number. All bars or forged blanks of starting material shall be subjected to nondestructive inspection using any of the following methods: Eddy current, Magnetic particle inspection (wet or dry), Liquid penetrant inspection, Ultrasonic testing, or Visual testing.

Applications

Nuts, bolts, screws, washers, studs, and Stud Bolts

Specifications

A-437 Alloy-Steel Turbine-Type Bolting Material Specially Heat Treated for High-Temperature Service

Grades: B4B (422), B4C, B4D (K14072)

Available Forms

• Bar
• Forge