摘要
Many of the high strength,high toughness steels in use or under development are alloy steels with dislocated lath martensitic structures.These microstructures are visually complex,and are difficult to categorize in the detail needed to clarify the structure-property relations.However,substantial progress has been made in recent years.In particular,it is now clear that the martensite block element sets the effective grain size that must be controlled to resist brittleness by cleavage fracture.In previous papers at this conference I have discussed the nature and importance of the block structure.In this study I discuss how the block size can be controlled by thermal treatments to achieve superior properties.
Many of the high strength,high toughness steels in use or under development are alloy steels with dislocated lath martensitic structures.These microstructures are visually complex,and are difficult to categorize in the detail needed to clarify the structure-property relations.However,substantial progress has been made in recent years.In particular,it is now clear that the martensite block element sets the effective grain size that must be controlled to resist brittleness by cleavage fracture.In previous papers at this conference I have discussed the nature and importance of the block structure.In this study I discuss how the block size can be controlled by thermal treatments to achieve superior properties.
