The effects of elements in precision bright tubes on high temperature temper brittleness are divided into:
(1) Impurity elements that cause high temperature temper brittleness of precision bright tubes, such as phosphorus, tin, antimony, etc.
(2) Alloy elements that promote or slow down high temperature temper brittleness in different forms and degrees. Chromium, manganese, nickel, silicon, etc. play a promoting role, while molybdenum, tungsten, titanium, etc. play a retarding role. Carbon also plays a promoting role.
Generally, carbon precision bright tubes are not sensitive to high temperature temper brittleness. Binary or multi-element alloy steels containing chromium, manganese, nickel, and silicon are very sensitive, and their sensitivity varies depending on the type and content of alloying elements.
The original structure of tempered precision bright tubes has a significant difference in sensitivity to high temperature temper brittleness of steel. The martensite high temperature tempering structure is the most sensitive to high temperature temper brittleness, followed by the bainite high temperature tempering structure, and the pearlite structure is the least.
Alloy elements such as manganese, nickel, and chromium co-segregate with the above impurity elements at the grain boundaries, promoting the enrichment of impurity elements and aggravating embrittlement. Molybdenum, on the contrary, has a strong interaction with impurity elements such as phosphorus, which can produce precipitation phases in the crystal and hinder the grain boundary segregation of phosphorus, which can reduce high-temperature temper brittleness. Rare earth elements also have similar effects to molybdenum. Titanium more effectively promotes the precipitation of impurity elements such as phosphorus in the crystal, thereby weakening the grain boundary segregation of impurity elements and slowing down high-temperature temper brittleness.
Precision Bright Tube
