低温环境下如何选择紧固件

1csss

在此MDMT下冲击试验不能豁免，螺母需选用SA-194 Gr.4+S3或SA-194 Gr.7+S3,但是最低使用温度不能超过-101℃

emperor620

1csss 发表于 2014-1-20 15:41
在此MDMT下冲击试验不能豁免，螺母需选用SA-194 Gr.4+S3或SA-194 Gr.7+S3,但是最低使用温度不能超过-101℃

也知道，不过这样会增加采购难度，所以还是想换材料

elonliu

等高手解答，再来学习

hiphil

如果用这个螺母肯定是要做冲击的，标准上已经说得很清楚了。
10.1 Bolts, studs, and stud bolts of Grades L7, L7A,
L7B, L7C, L43, L1, L70, L71, L72, and L73 shall be
equipped with ferritic alloy nuts conforming to Grade 4
or Grade 7 of Specification A 194/A 194M or a grade of
steel similar to the studs. Grade 7M nuts at a hardness not
exceeding 235 HB (or equivalent) shall be used with Grade
L7M bolts, studs, and stud bolts. All nut materials, including
those which may be supplied under Specification
A 194/A 194M, shall be subject to the impact requirements
of this specification in the following manner: impact tests
shall be made on test specimens taken from the bar or
plate from the heat of steel used for manufacturing the
nuts, and heat treated with the nut blanks.
如果想不冲击的话，只能按照下面的条款选择不锈钢的了
10.3 If the purchaser requires nuts with a Charpy impact
energy absorption of not less than 20 ft · lbf [27 J] at
temperatures below −150°F [−100°C], he may require that
the nuts conform to Grades 8, 8C, 8M, 8P, 8T, 8F, 8LN,
or 8MLN of Specification A 194/A 194M.

emperor620

hiphil 发表于 2014-1-23 14:27
如果用这个螺母肯定是要做冲击的，标准上已经说得很清楚了。
10.1 Bolts, studs, and stud bolts of Grade ...

请问此条是规范中哪一条呢

hiphil

emperor620 发表于 2014-1-23 15:33
请问此条是规范中哪一条呢

ASME ⅡA里SA-320里面的

我爱爬山

所以还是换材料更容易些吧