如何编制用冷拔盘料ML35（铆螺）冷挤压成形螺栓的热处理工艺？_爱下问搜题

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问题问答题简答题

如何编制用冷拔盘料ML35（铆螺）冷挤压成形螺栓的热处理工艺？

答案

参考答案：

为改善冷镦性能先将盘料进行球化处理，采用普通球化退火：盘料入炉后以（100-150）℃的速度升至（750-770）℃，保温（4-6）小时，随后以（20-30）℃的冷却速度控制降温至680℃，再随炉冷至550℃出炉空冷。对于8.8级以上的性能等级的螺栓需要进行调质处理，调质工艺要根据设备、装载方式、螺栓尺寸等条件制定，淬火温度（840-850）℃，散装时加热保温时间按散装有效厚度计算（1-1.2）min/mm，冷却介质宜采用25%NaOH水溶液。450℃回火后空冷。在连续式淬火炉的额定生产率下，螺栓在炉内有效加热区中经过的时间一般为（20-60）分，小直径、或料层薄取下限。

辨析题

合作无处不在，无时不有。合作是一种力量，也是一笔财富。善于合作，是时代的要求；善于合作，往往有助于事业的成功。

辨析：合作比竞争更为重要。

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完形填空

完形填空(共20小题；每小题1.5分，满分30分)
阅读下面短文，从短文后各题所给的四个选项(A、B、C、D) 中，选出可以填入空白处的最佳选项。
We were standing at the top of a church tower. My father had __1__ me to this spot in a small town not far from our home in Rome. I wondered __2__.
“Look __3__, Elsa,” Father said. I gathered all my __4__ and looked down. I saw the square in the centre of the village. And I saw the crisscross(十字形) of twisting, turning streets leading to the __5__. “See, my dear,” Father said gently. “There is more than one way to the square. __6__ is like that. If you can’t get to the place where you want to go __7__ one road, try another.”
Now I understood why I was there. __8__ that day I had begged my mother to do __9__ about the terrible lunches that were served at school. But she __10__ because she could not believe the lunches were as __11__ as I said.
When I __12__ my father for help, he would not help. _13__, he brought me to this high tower to __14__ me a lesson — the value of an open, searching mind. By the time we reached home, I had a __15__.
At school the next day, I _16__ poured my lunch soup into a bottle and brought it home. Then I asked our cook to _17__ it to mother at dinner. The plan __18__ perfectly. She swallowed one spoonful and said, “The cook must have gone mad!” Quickly I told what I had done, and mother said firmly that she would take up the matter of lunches at school the next day.
In the years that followed I often remembered the lesson father taught me. I began to work as a fashion designer two years ago. I wouldn’t stop working __19__ I tried every possible means to my goal. Father’s wise words always __20__ me that there is more than one way to the square.

A．belonged to