Microstructure shall consist of at least 90% martensite tempered to the required hardness/strength level. A maximum of 10% bainite is acceptable provided toughness is not adversely affected.

• 微观组织最少含90%25回火马氏体以满足硬度强度要求，最大允许10%25贝氏体，以便提供强韧性能而不起反作用。