Observations showed that the micro-structure of the steel after forging or high temperature rolling was composed of low-carbon martensite, a little part of bainite and residual austenite.
The existence and amount of small isolated martensite between the acicular ferrite play an important role in determining the tensile strength and lowtemperature impact toughness of the steels.
其中针状铁素体之间细小的马氏体的存在与数量对钢的抗拉强度和低温冲击韧性起关键作用。
3
Reversed austenite, carbide and martensite transformed by the reversed austenite also have significant influence on low-temperature toughness of 9Ni steel.