【判断题】渗碳钢的合金调质钢的含碳量一般<0.25%。< /div>
【单选题】Question 30 Choose the correct letter ,A-C. What is the tutor trying to do in the tutorial?
A.
describe one selection technique
B.
criticise traditional approaches to interviews
C.
illustrate how she uses personality questionnaires
【单选题】常用渗碳钢一般为低碳钢或低碳合金钢,含碳量要求在()。
【单选题】为增加钢件表层的含碳量和一定的碳浓度梯度,将钢件放在含碳的介质中加热并保温,使活性碳原子渗入表层的热处理工艺称为渗碳。渗碳用钢一般采用含碳量为()的低碳钢或低碳合金钢
【简答题】choose the correct answer for the sentences in column A