选择题 1.一般合金钢淬火比碳钢加热时间a.长些,b.短些,c.一样。 2.高温计下面的黑点是代表a.炉温与室温之差,b.高温计本身温度。 3.用氧炔(火刀臼)进行局部退火或热点校直时,应先开乙炔气,点着火后再开氧气,关火时应a.先关乙炔气再关氧气,b.先开氧气再关乙炔气。 4.奥斯田体比马顿赛体是a.硬些,b.软些。 Multiple choice 1. General alloy steel quenching than carbon steel heating time a. Longer, b. Shorter, c. The same. 2. The black point below the pyrometer represents a. Difference between the furnace temperature and the room temperature, b. The temperature of the pyrometer itself. 3 with the acetylene (acetabulum) for local annealing or hot straightening, you should first open acetylene gas, point the fire and then open the oxygen, turn off the heat should be a. Oxygen then off acetylene gas. 4. Otis field than Matton sports body is a. Hard, b. Soft.