What is the reason that the cast iron is too fragile?
Pig iron is relatively crisp, low temperature is more, and may also be operational problems, to standardize operations!
Your situation may be that it contains more carbon, or contains excessive amounts of parathion and dissolved copper.
It refers to some steel 400 to 500 DEG C temperature range after long-term stay at room temperature impact value have obvious decline. When high temperature does not show brittleness, only when the impact test at room temperature can the brittleness rise, the normal value can decrease by more than 50% to 60%. Low alloy chromium nickel steel, manganese steel, copper bearing steel to hot brittleness. When the sulfur content reaches a certain level, there will be the nature of hot brittleness.
There are two kinds of iron brittlenessOne is cold brittlenessOne is hot shortnessThe impact value of cold brittle metal material at low temperature decreases obviously. Most of them were caused by high phosphorus content. It was similar to the sinking of the Titanic in that year. Later, it was analyzed that the cold brittleness of the ship plate was caused. In addition, carbon can also increase the cold brittleness and aging sensitivity of steel, and reduce the plasticity and impact resistance of steel.
