GB/T 223.58-1987 is a standard method for the determination of manganese in steel and alloys. It uses the sodium arsenite-sodium nitrite Titrimetric method, which is clearly applicable to all kinds of steel and alloy samples. The standard describes the principle of using specific chemical reactions to determine manganese content by titration of sodium arsenite and sodium nitrite. Specify the required equipment, such as Burette, etc., and various reagents. Detail the sample pretreatment steps, such as dissolve, separate interfering elements, etc., followed by the titration operation process, including titration speed, end point judgment, etc. This standard can accurately determine the manganese content in steel and alloys, providing key data for steel production and mass evaluation.