Forammunition to break through, artillery shells need to be hardened by adding certain minerals to the steel.
为了让炮弹能够打穿，弹壳的钢里需要加入一定的矿物质来增加硬度。
2
To assess the reliable stockpile lifetime of air ammunitions scientifically, a series of evaluation method forammunition were established by researching a great deal of test data.