国产精品毛片一区二区三区,国产女人被狂躁到高潮小说,国产91精品一区二区麻豆网站,日韩精品人妻丰满-无码久久

First, fastener (bolt, bolt and stud) material request (GB/T3098.1-2000)

1) the boron content may reach 0.005%, its non-effective boron may by the increase titanium and (or) the aluminum control.
2) these performance rating permission uses easily to cut the manufacture, its sulfur, the phosphorus and the lead biggest content is: Sulfur 0.34%; Phosphorus 0.11%; Lead 0.35%.
3) to guarantee that the good hardenability, the diameter of screw surpasses 20mm the fastener, must use to 10.9 level of stipulation steel.
4) the carbon amount is lower than 0.25% (ladle analysis) low-carbon alloyed steel's manganese lowest content is: 8.8 levels: 0.6%; 9.8th, 10.9 and 10.9 levels: 0.7%.
5) this product should increase a horizontal line symbol under the performance rating code number. 10.9 levels should tally to 10.9 level of stipulation all performance, but low along fire temperature to it, in raises ridicules the temperature under the condition, will cause the varying degree the stress to weaken.
6) uses in this performance rating the material being supposed to have the good hardenability, guaranteed fastener thread section core section before quenching, the tempering obtains the approximately 90% martensite organization.
below 7) the alloy steel should include in the far element one kind of element at least, its smallest content is: Chromium 0.30%; Nickel 0.30%; Molybdenum 0.20%; Vanadium 0.10%
8) considers the withstanding tensile stress, 12.9 levels of surfaces do not allow to have the white phosphorus accumulation level which the metallography can determine.
9) this chemical composition and in drawing temperature still at investigation and study.

Second, nut
1. nut (fine tooth thread) material specification (GB/T3098.2-2000)

3. riveting nut's material (GB/T17880.6-1999)

Third, clamping screw nail's material specification (GB/T3098.3-2000)

Note: The performance rating 45H clamping screw nail when can satisfy in the GB/T3098.3-2000 standard the 6.3rd stipulation guarantee torque request, may also use other material manufacture.

Fourth, uses the screw joint heat-resisting vice-(3098.8-92)
Is suitable in both can along with the high temperature, the alternating load, and must maintain in the quite great degree the pretightening up force and bears the fastener material which the fatigue strength under the operating mode condition uses to request.
1. uses in is bigger than +300℃ material, sees the table.

1) the bolt, the stud should compared to tired mother's degree of hardness high (for example high 30-50HB).
2) the stress drive pipe's material, the recommendation uses with the stud same material.

2. the material material should pass through the low time of organization's inspection. And, is generally loose, the center to be loose and the square shape segregation do not surpass the GB1979 stipulation second-level.

Fifth, stainless steel fastener's material specification
Bolt, bolt and stud (3098.3-2000), nut (3098.15-2000), clamping screw nail (3098.16-2000)
Gives according to the related national standards production's fastener suitable stainless steel material in table 1.
Only if supply and demand both sides have the agreement in addition, the chemical composition should, in the steel group stipulated in the scope, chooses by the manufacturer.
In has the situation which the intercrystalline corrosion favors, recommends carries on the experiment according to ISO3651-1 or the ISO3651-2 stipulation. Under this situation, the recommendation uses the stability mode A3 and A5, or uses the carbon amount not to surpass 0.03% A2 and a4 stainless steel.

Table 1 stainless steel category and chemical composition

1) besides already indication, was a maximum value.
2) the sulfur available selenium replaces.
3) like the nickel content is lower than 8%, then the manganese smallest content must be 5%.
when 4) the nickel content is bigger than 8%, does not give the limit to the copper smallest content.
5) the molybdenum content possibly appears in manufacturer's instruction booklet, but to certain use situation, if has the essential definition molybdenum limit content, then must indicate in the order form by the user.
6) the molybdenum content possibly appears in manufacturer's instruction booklet.
7) like the chromium content is lower than 17%, then the nickel smallest content should be 12%.
8) achieves 0.03% austenite stainless steel to the greatest carbon amount, the nitrogen content is highest may achieve 0.22%.
9) to organize stably, the titanium content should ≥5×C%-0.8%, and should according to this table suitable symbol or the niobium and (or) the tantalum content should ≥10×C%-1.0%. And should symbolize suitably according to this table.
10) to large diameter product. In order to achieve the stipulation the mechanical property, in manufacturer's instruction booklet, possibly has the high carbon content, but should not surpass to the austenite steel 0. 12%.
11) the titanium content is possibly ≥5×C%-0.8%
12) the titanium content is possibly ≥10×C%-1.0%

Sixth, non-ferrous metal manufacture bolt, bolt, stud and nut
Is suitable in various performance rating non-ferrous metal fastener's material trademark: (GB3098.10-93)

According to supply and demand both sides agreement, when the supplier can guarantee the mechanical property, may use outside the table the material.
In order to guarantee that the fastener meets the related mechanical property requirement, by the manufacturer determined whether to carry on the heat treatment.

Attaching: Suitable international standard material trademark

Seventh, from attacks a kind of bolt
1. from drills tapping screw's material (GB/T3098.11-1995)

Note: The permission boron's content scope is: 0.05-0.30%

2. from pushes the bolt (including from attacks gib screw) (GB3098.7-2000)
From pushes the bolt application cementation cold dui manufacture. Table 1 gives the material chemistry ingredient is only guidance.

Table 1 chemical composition