ASTM A878/A878M-19(2024)

Die Annotation des Normtextes ASTM A878/A878M-19(2024) :

This specification covers the highest quality of round modified chromium vanadium alloy steel valve spring wires, uniform in quality and temper, intended for the manufacture of valve springs and other springs requiring high-fatigue properties when used at moderately elevated temperatures. This wire shall either be in the annealed and cold-drawn or oil-tempered condition. The steel shall be subjected to continuous casting and be free from detrimental pipe and undue segregation. Heat and product analysis shall conform to the chemical requirements for carbon, manganese, phosphorus, sulfur, silicon, chromium, and vanadium. Mechanical properties shall be determined by the following: annealing and cold-drawing, oil tempering, wrap testing, and special surface inspection. In the oil-tempered condition, steel shall conform to the tensile requirements for different wire diameters. Metallurgical characterization shall include surface condition, decarburization, and inclusion content. The wire or wire rod shall conform to the maximum inclusion content requirements for the surface and core zones.


Keywords:
alloy, modified chromium vanadium, valve spring, wire,, ICS Number Code 77.140.25 (Spring steels)