16Mo3 steel plate often exists in the form of iron sulfide in steel, and it is distributed in the grain boundary in a network, thus significantly reducing the toughness of the steel. The eutectic temperature of iron plus iron sulfide is relatively low (985°C).
Therefore, during the hot working of 16Mo3 steel plate, the starting temperature of the processing is generally 1150~1200℃, and the eutectic of iron and iron sulfide has already melted, resulting in cracking of the 16Mo3 steel plate during processing. This phenomenon is the so-called "hot brittleness of sulfur" . This property of sulfur causes hot cracks in the 16Mo3 steel plate during welding.
Therefore, the sulfur content in 16Mo3 steel plate is generally strictly controlled. The main difference between ordinary carbon steel, high-quality carbon steel and high-quality steel is the amount of sulfur and phosphorus.