求焊接毕业设计外文文献,高分奖励
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发布时间：2022-05-01 22:20
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热心网友
时间：2022-06-24 07:08
Range
This technology is applicable to general instrial and civil construction projects in the steel structure proction and installation of hand-Arc Welding works.
Construction preparations
2.1 materials and major equipment:
2.1.1 welding electrodes: its choice of models according to design requirements, we must have quality certificate. Welding, as required prior to baking. Prohibited the use of drugs shedding skin, core rusty welding electrode. No design requirements, welding steel Q235 to choose E43 series of structural steel welding rod, welding 16 Mn steel to choose E50 series of low-alloy steel welding rod, welding important structure to use low-hydrogen electrode (alkaline electrode). Brochures on the request of baking, Add to Baowen Tong, with the use of admission. Acidic and alkaline electrode electrode not mixed use.
2.1.2 arc plate: groove connection required arc plate, arc-type material and groove with the welding of the same.
2.1.3 major equipment: welding machine (TAC, DC), the welding line, welding clamp, face masks, Xiaochui, electrode oven, the electrode Baowen Tong, wire brush, stone cotton cloth, such as temperature dollars.
2.2 operating conditions
2.2.1 familiar with the drawings, done welding technology Jiaodi. 2.2.2 before welding welder certification should check the expiration date, should prove welder to take the welding work.
2.2.3 spot welding power supply should meet the electricity demand.
2.2.4 ambient temperature below 0 ℃, the preheating, after the hot temperature should be determined in accordance with technology test.
Operation of
3.1 Process
Operating ready → Arc Welding (-welding, welding, Wang welding, Yang welding) → weld inspection
3.2 arc welding steel structure:
3.2.1-welding
3.2.1.1 choose the right welding process, welding rod diameter, welding current, welding speed, the length of arc welding, welding technology through pilot certification.
3.2.1.2 liquidation Welded Joints: welding inspection groove, the assembly space to meet the requirements, positioning it firmly welding, weld around the oil pollution may be, of rust.
3.2.1.3 baking electrode should meet the required temperature and time, remove from the oven in the electrode, on the electrode Baowen Tong, with the use of admission.
3.2.1.4 welding current: According to the thickness of welding, welding level, electrode models, diameter, welder proficiency and other factors, select suitable welding current.
3.2.1.5 arc: Kok point arc welding ups and downs in the weld should end, to more than 10 mm, should not be casually playing arc, tinder-igniting immediately after the electrode from the seam zone will be opened so that the electrode and components Inter 2 ~ 4 mm to maintain a gap arc. Butt Weld and docking and the combination of angle to weld, located at both ends of the arc-welding leads and board, must arc welding to the board after the arc welding, half-way joint weld joints should be in the front 15 ~ 20mm igniting the tinder, welding pieces after preheating will return to weld electrode at the beginning of the pool to fill the requirements of thickness, before welding forward.
3.2.1.6 welding speed: isokinetic welding requirements to ensure that weld thickness, width uniform, masks, read from the pool of molten iron slag and maintain equidistance (2 ~ 3 mm)
3.2.1.7 welding arc length: electrode under different models identified, the general requirements of the same arc length stability, acid electrode is generally 3 ~ 4 mm, alkaline electrode is generally suitable 2 ~ 3 mm.
3.2.1.8 welding angle: According to weld the two pieces of the thickness determined that welding two 000-point, first welding electrode and the direction of the angle to 60 ~ 75 °; electrode and the second is the angle between two welding about the situation When welding pieces of equal thickness, the angle between the electrode and welding pieces are 45 °; When the thickness ranging from welding, welding electrode and thick pieces of angle between the side should be more than welding electrode and thinner pieces of angle between the side of .
3.2.1.9 to arc: each seam welded to the end, the hole should be filled arc, to welding direction opposite direction with arc, arc welding, Hang left inside to prevent the arc Hang bite of meat. Welding completed, should be used with arc-gas cutting and grinding formation, while the use hammer down.
3.2.1.10-Java: The whole of welding seam after removal of slag, the welder self-inspection (including the appearance and weld size, etc.) is no problem, before relocation to welding.
3.2.2 welding: basic operation and the process of welding the same level, but should pay attention to the following questions:
3.2.2.1 under the same conditions, welding power than small-welding current 10 percent to 15 percent.
3.2.2.2 use of short-arc welding, arc length is generally 2 ~ 3 mm.
3.2.2.3 perspective based on welding electrode thickness determined. Welding two pieces of equal thickness, the electrode and the electrode around the direction of both the angle between 45 °; two pieces of thickness ranging from welding, welding electrode and thick pieces of angle between the side of the thin side should be larger than the angle. Electrode with the vertical plane formed 60 ° ~ 80 ° angle, slightly upward arc, toward pool centre.
3.2.2.4 to arc: When welding to the end, the arc of a row pits will fill the arc, the arc moved to the central pool stopped arc. Prohibited the arc Hang left side. In order to prevent bites of meat, should be suppressed transform arc welding rod angle so that the welding rod and welded pieces of vertical or slightly down from the arc blowing.
Wang welding 3.2.3: basic and same-welding, welding current conditions compared with the current small-welding of 10% to 15%, Arc-2 ~ 4 mm. Electrode perspective, Wang when welding electrode should Tilt Down, for their point of 70 ° ~ 80 °, to prevent hot metal falling. According to weld the two pieces of different thickness, can be properly adjusted electrode perspective, with the welding electrode to the direction of 70 ° ~ 90 °.
Yang welding 3.2.4: basic and welding, Wang welding the same, the electrode and welding pieces of angle and thickness of the welding, and welding electrode into the direction of 70 ° ~ 80 ° angle,宜用small current, short arc welding.
3.3 winter low temperature welding:
3.3.1 in the environmental conditions of temperature below 0 ℃ under the Arc, in addition to compliance with the relevant provisions of ambient temperature welding, welding process parameters should be adjusted so that the weld and heat-affected zone slow cooling. Wind over four, the wind should take measures to cool after welding of the joints, should be avoided encounter snow and ice.
3.3.2 welded steel structure in order to prevent cracks, should be preheated, preheat to control the temperature between layers. When the temperature in the workplace 0 ℃ below, the process should be carried out tests to ascertain preheating appropriate, after the hot temperature.
Quality Standards
4.1 ensure that the project
4.1.1 welding materials should be consistent with the design requirements and the relevant standards, should check the quality certificates and baking records.
4.1.2 The welder must pass the examination, inspection welder corresponding welding conditions of certification and testing dates.
4.1.3 Ⅰ, Ⅱ-Weld must be approved by the detection test, and should meet the design requirements and construction standards and inspection requirements, inspection Weld Inspection report.
4.1.4 Weld surface Ⅰ, Ⅱ-weld should not crack, of welding, Shaochuan, pits and other defects arc. Ⅱ-Weld may be the surface pores, slag, the arc pits, cracks, scratches and other defects arc, and weld Ⅰ level may be biting edge, not for welding defects.
4.2 basic items
4.2.1 Weld Appearance: Weld uniform appearance, welding, and welding, welding and smooth transition between the basic metals, welding slag and flying purge clean.
4.2.2 surface porosity: Ⅰ, Ⅱ-Weld does not allow; Ⅲ-weld seam length of each 50 mm in diameter, allowing ≤ 0.4 t; and ≤ 3 mm stomatal 2; ≤ 6 times the distance between stomatal aperture.
4.2.3 biting edge: Ⅰ-Weld does not allow.
Ⅱ-Weld: bite-depth ≤ 0.05 t, and ≤ 0.5 mm, for the length of ≤ 100 mm, and both sides of bite-chief of ≤ 10% weld length.
Ⅲ-Weld: bite-depth ≤ 0. Lt, and ≤ lmm.
Note; t joining the thinner the thickness.
4.3 to allow deviation project
Weld Ms high b <20 0.5 ~ 2 0.5 ~ 2.5 0.5 ~ 3.5
1 Butt Weld (mm) b ≥ 20 0.5 ~ 3 0.5 ~ 3.5 0 ~ 3.5 to <0.1 t and <0.1 t and <0.1 t and welding more than 2.0 of not more than 2.0 of not more than 3.0 welding angle size hf ≤ 6 0 ~ +1.5 weld seam 2 Kok (mm) hf> 6 0 ~ +3 of Weld Ms high hf ≤ 6 0 ~ +1.5 Regulation (mm) hf> 6 0 ~ +3 seized three T-shaped joint weld combination , Cross joints, joint angle> t / 4 check welding angle from the size of the weight ≥ 50 t, mid-level working crane beam T-shaped connector t / 2 and ≯ 10
Note: b width for Weld, t joining the thinner the thickness, hf for welding angle size.
Proct Protection
Not allowed to hit 5.1 hit after welding joints, not just to the End of steel welding on the water. Low temperature should take measures to alleviate the cold.
5.2 arbitrarily not be allowed outside the base metal in the weld on the arc.
5.3 various components correction may be good after welding, and not free to move Sizing Block and Kaju, a component size to prevent bias. Concealed parts of Weld must apply for concealed End acceptance proceres only after the next, hidden processes.
5.4 low-temperature welding slag not immediately clear, and so should cool down after the weld.
Should pay attention to the quality problems
Size exceed 6.1 to allow deviation: Weld length and width, width, thickness inadequate, the centerline offset, bending, and other deviations, should strictly control the welding parts of the relative position of size, rear-qualified welding, welding operation at carefully.
6.2 weld cracks: To prevent cracking, should be selected for the welding process parameters and welding proceres to avoid using high-current, do not suddenly off, weld joints should take 10 ~ 15 mm, welding in the wood allow moving, percussion welding Pieces.
6.3 surface porosity: electrode to the required temperature and time for baking, welding region must clean up, welding process of choosing the appropriate welding current, lower welding speed so that the pool of gas entirely escaped.
Weld slag 6.4: multi-layers of welding should be clean welding slag removal, transport operators should be correct, appropriate length. Note the direction of the flow of slag, a basic electrode, on the need to remain in the slog slog behind.
Records
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时间：2022-06-24 07:08
