These conditions are improved after tightening to the yield limit, which naturally improves the bolting resistance of the bolted joint. Although the torque method can reach the plastic zone, the torque method has the disadvantage that the plastic elongation of the bolt is uncontrollable. Tilt tightening method This is also a tightening method that can reach the plastic zone. The plastic domain cornering method requires the bolt to be tightened to the working condition just before the yield limit point, but it is an artificially determined point, if it can be measured according to the tightening process. The data derives the position of the yield point better. It is shown that the pre-tightening force varies with the rotation angle, and the inclination is also different. When the bolt tightening process is divided into three regions, the change of the rotation angle can be described as a torque gradient variation curve. The torque gradient is increasing in the starting zone, and the torque in the tightening zone is increasing, but the torque slope is no longer increasing or decreasing (the end of this zone is the bolt begins to yield). The torque in the yield zone rises slightly, and the torque slope drops significantly, eventually the bolt is damaged at the section shrinkage. When the bolt yields, the torque slope changes very rapidly, and the slope drops sharply from the maximum 70% 80% to 25% 30%, so the yield limit can be effectively measured by measuring the swing angle, that is, the slope curve. Bolt tightening of the tower crane standard section The tower crane is a large-scale mechanical equipment that is often used during construction. It is very important to connect the standard section of the tower crane during on-site construction. If the bolt connection fails, a major engineering accident will occur. According to the author's practice, the following points should be noted when bolting the standard section of the tower crane.
Tower cranes are often disassembled and assembled, and the bolts used should have reusable functions. The amount of plastic elongation caused by each tightening should generally be screwed to the limit just after the yield. In order to obtain better reusability, the amount of deformation of the tightened part should not be too large when determining the corner. Therefore, not only the limit torque value and the corner error are small, but also the accuracy of the thread pair is improved.
Stainless Steel Coil
Characteristics of Stainless Steel Coil :
1. stainless steel product specifications complete, diverse materials; 2. high precision in size 3. excellent surface quality, good brightness; 4. with strong corrosion resistance, high tensile strength and fatigue strength; 5. pure steel, stable chemical composition, inclusion content is low.
The grade of the stainless steel coil: 201,202,301,304,304L,
316,316L
Description of stainless steel coil:
Surface:2B,BA,No1
Thickness: 0.12-2mm
Width:1000/1029/1500/1800/2000mm
Coil
weight:3-5tons or as your request
Application:food factory, chemical, medical equipment Packing:wooden pallet, or
as the client's requirements
MOQ: 10tons
Payment term: T/T, L/C, Western Union
Stainless Steel Coil
Stainless Steel Coll,Stainless Steel Coils,Stainless Steel Coil Wire,Stainless Steel Coil Nails
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