棚车用的从板以前是用两个砂型铸件焊接而成。现在改用较好和更经济的锻钢制造。从板要承受一组车辆在与另一组车辆连挂碰撞时所产生的全部力量。四年前,美国 Berwick Forge & Fabri-cating 锻制了第一个从板后曾送至 Pittsburgh实验室进行了压力试验。试验表明,它不仅超过了计算上要求,而且可能会损坏试验机。零件安装在承受列车运行和调车时产生冲击力的车辆底架上,该冲击力可能超过680吨。用锻造法生产从板的另一理由是生产率较 The box car used from the plate before the two sand castings welded together. Now switch to better and more economical forged steel manufacturing. The slab must withstand the full force generated by a set of vehicles in a collision with another set of vehicles. Four years ago, Berwick Forge & Fabri-cating of the USA forged the first pressure test that was sent to Pittsburgh Labs from the slab. Experiments show that it not only exceeds the computational requirements, but also may damage the testing machine. The parts are mounted on a chassis of the vehicle that is subject to impact on train operation and shunting, which may exceed 680 tons. Another reason for using forging to produce slabs is productivity