BT2

①碳含量每降低0.01%，最大锰含量则增加0.04%，允许最大锰含量到1.1%
②此牌号成分使得其大截面厚度铸钢件有足够的淬透性

A=for anneal by heating to a temperature above the AC3 and cool in the furnace
N=for normalize by heating to a temperature above the AC3 and cool in still air
OQ=for quench into oil from a temperature above the AC3
WQ=for quench into water from a temperature above the AC3
AH=for air harden by heating to a temperature above the AC3 and cool in air at a rate fast enough to produce a hardened microstructure
T=for temper by heating to a temperature below AC1
ST=for solution treat by heating to temperature high enough to dissolve and any intermetallic phases followed by a rapid cool.

①Where, due to the mass or design, it is not practicable to liquid quench the castings, it may not be possible to achieve the specified impact properties. In such cases the values to be obtained should be agreed between the manufacturer and purchaser at the time of enquiry or order.