【简答题】1 简述焊条选用的一般原则。 2 用低合金结构钢 Q550 钢板焊接一压力容器,所用材料的化学成分为: W C =0.18%, W Mn =1.8% , W v =0.12%, W Mo =0.2% , W Cr =0.6% (其它合金元素含量忽略不计), W p 、 W s < 0.045% 。计算碳当量,并判断其可焊性。
【简答题】完形填空。 Tom bought shoes from the shoe factory and tried to sell them to other people. There were not many 1 in the small villages. People there didn't 2 to go to town to buy shoes' So Tom 3 a lot of sh...