问题 问答题 简答题

何谓非调质钢,有何工艺特点?

答案

参考答案:

非调质钢选用中碳微合金化成分配方,加入一种或多种碳化物形成元素,如V、Nb和Ti等,常用非调质钢牌号有45MnV、40MnVTi、35MnVNb和49MnVS3等。工件可不经调质处理,零件所需的强度和韧性由控制锻造工艺获得,通常采用大的变形量锻造,以及控制较低的仃锻温度,以获得硬度较高的变形珠光体组织,替代调质形成的回火索氏体组织。非调质钢适用于受力条件不太恶劣的零件。

阅读理解

阅读理解。

      Taiwanese singer Stefanie Sun (孙燕姿) looks just like any other young girl. She has short hair, a clear

face and a sweet smile. However, there is something about her that makes her very special: her voice. No

one else can sing like she can. Now, Sun is a bright star. She has released many albums (专辑).

      Sun was born in Singapore. When she was a child, her father told her:"A person should always be good

at something in life, so they have something to do for a hobby." Sun chose to learn to play the piano when

she was only five. Then, she took up kick-boxing (搏击操) because she felt she was thin and wanted to make

herself stronger. 

      She often sings about the pain and happiness of growing up. The simple but true feelings in her music are

loved by teens. "Sun may be a star, but she seems like a normal girl. She is close to us," said Zhu Liying, 15,

a Beijing student."Her songs give me courage."

      Eventually, the star was tired because she had worked so hard. She stopped singing for a while and had

a one-year holiday to travel. "I won't give up singing. I just want a rest and to try something new. I hope to

make better music when I come back," Sun said then.

      Now she is working hard again to let her fans hear more beautiful music.

1. Which is NOT true about Sun? [ ]

A. She has short hair.

B. She always has sweet smiles.

C. Her face looks clear.

D. She is a very famous actress.

2. The underlined word "released" in the first paragraph means _____. [ ]

A. made sth. public

B. set free

C. let out

D. made up of

3. Sun learned kick-boxing when she was still a child because _____. [ ]

A. she wanted to be a dancer

B. she wanted to get stronger

C. she enjoyed dancing

D. she wanted to be famous

4. Teenagers love Sun's songs because _____. [ ]

A. her songs are about the pain of growing up

B. she looks clear and is kind to all her fans

C. the feelings in her songs are simple but true

D. her songs are about love and friends

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