《h型钢t型钢自动埋弧焊工艺守则（Code for automatic submerged arc welding of H steel T section steel）.doc》由会员分享，可在线阅读，更多相关《h型钢t型钢自动埋弧焊工艺守则（Code for automatic submerged arc welding of H steel T section steel）.doc（10页珍藏版）》请在三一文库上搜索。
1、h型钢t型钢自动埋弧焊工艺守则（Code for automatic submerged arc welding of H steel T section steel）Code of practice for automatic submerged arc welding of H and T steelFour, H, steel, T steel automatic submerged arc welding process code1, preface1.1 automatic submerged arc welding is a highly efficient mechanical
2、welding process. It has high penetration, high deposition efficiency and stable welding parameters. Welding quality is stable and reliable is its outstanding features;1.2 the code specifies the basic requirements for submerged arc welding machines and the basic specifications that must be observed a
3、t work.2, automatic submerged arc welding2.1 automatic submerged arc welding is first and foremost a qualified manual arc welding welder. Must have basic knowledge of manual arc welding, and master basic operation skills of manual arc welding;2.2 automatic submerged arc welding machine should unders
4、tand and master the structure and working principle of welding equipment and its accessory equipment which is produced in this production process;2.3 automatic submerged arc welding machine shall have full knowledge and mastery of the basic knowledge and operation skills of automatic submerged arc w
5、elding;2.3.1 basic knowledge about the process and principle of automatic submerged arc welding;2.3.2 on the commonly used automatic submerged arc welding material and flux of knowledge;2.3.3 knowledge of groove form and assembly relation of submerged arc welding;2.3.4 knowledge of automatic submerg
6、ed arc welding process;2.3.5 knowledge of common metal materials;2.3.6 knowledge of proper selection of welding parameters for submerged arc welding;2.3.7 knowledge of common defects in automatic submerged arc welded joints and their prevention;2.3.8 knowledge of safety technology in automatic subme
7、rged arc welding;2.4 automatic submerged arc welding, welders must be skilled in automatic submerged arc welding operation skills;2.2.1 correctly select welding equipment and auxiliary equipment according to production plan and process;2.2.2 correctly select welding material according to production
8、plan and process;2.2.3 correctly adjust and use welding equipment and auxiliary equipment according to production plan and process;2.2.4 correctly adjust welding process parameters according to production plan and process;2.2.5 correctly judge whether the welding process is correct according to the
9、instrument and the information feedback in the arc area;2.2.6 according to the appearance of the cold wind defects, correctly judge the cause of the defect, can promptly eliminate defects;2.2.7 eliminates defective welds and correctly completes the repair work.3. preparation before welding3.1 check
10、the size and shape quality of the workpiece transferred by the process;3.2 review the technical conditions of automatic submerged arc welding (including the integrity of welding equipment and auxiliary equipment and process conditions);3.3 specification of technological conditions:3.3.1 each solder
11、1000 meters (about 10 shifts) must replace the qualified welding nozzle, its material and size should meet the technical requirements;3.3.2 flux can be recycled, the culprit flux must remove impurities, must remove the iron impurities, it must clear a fence every magnet;3.3.3 recycled fluxes must be
12、 filled with new fluxes each time, with an average of 1:1 of the old and new fluxes;3.3.4 mixed flux, 1500 elongation per weld, must be completely replaced (about 15 shifts), replacement of the old solder can not be put into production again;3.3.5 fluxes used for the manufacture must be strictly pro
13、cessed according to process requirements, with a temperature of 200250 degrees,Time is 2 hours, no drying flux is strictly prohibited;3.3.6 welding wire welding torch, every 2000 meters of welding extension must be changed surface use, every 4000 meters extension of rice, then replace the new wire f
14、eed wheel, the maintenance of the feeding wheel is strictly prohibited to put into production again;3.3.7 welding pipe must be straight, not bent, bent to repair, repair welding pipe more than wire pipe center line in the same axis within the tolerances of less than 3mm;3.3.8 welding wire should be
15、neatly placed in the wire tray;The 3.3.9 welding wire has the wire letting plate, enters the welding torch through the guide wire tube, the movement trajectory should be smooth, according to the working condition, should choose the bigger radian and reduces the arc number.3.4 the welding position of
16、 this process is not ship type welding. It is characterized by beautiful welding seam, large deposited metal and high working efficiency;3.5 before placing the workpiece, move the welding equipment to a safe position and lift the welding torch to a safe height;3.6 the workpiece should be placed clos
17、e to the work table, parallel to the walking path of the welding cart. Keep the guide in close contact with the workpiece and check for any obstacles in front of the steering device3.7 select process parameters3.7.1 welding current: when other conditions remain unchanged, under normal conditions, th
18、e weld penetration is basically proportional to the welding current;3.7.2: arc voltage and arc arc voltage is proportional to the length, with the increase of arc voltage, the weld width increased and the penetration and more than slightly reduced, the arc voltage of different polarity, different in
19、fluence to the weld width. In submerged arc welding, a certain welding current should keep the arc length within a certain range to ensure the stability of the arc;3.7.3 welding speed: mainly over welding joints. The welding speed is big, the welding unit length, the deposition quantity is small, th
20、e welding speed is small, the welding unit length, the deposition quantity is big. In actual production, in order to increase productivity, the arc power must be increased while increasing the welding speed;4, welding4.1, welding torch welding nozzle to the application of solder joints have a proper
21、 distance, the height of 9 times the diameter of wire;4.2, the welding wire spit out, with pliers clamp off, so that exposing new section;4.2 switch on the switch, the flux will be covered tightly in the welding area, and the arc shall not be exposed;4.3 in the arc arc arc trip, and the body weld we
22、ld should be a smooth transition, with a set of process parameters when arc. In the end should be arc plate;4.5 open the flux recovery mechanism. Attention to the timely recovery of flux;4.6, welding process should pay attention to observe the formation of welding slag, observe the appearance of the
23、 weld quality, such as found abnormal, timely adjustment;In the course of 4.7 multi pass welding, each weld shall be removed in time. If the welding quality defects are found, the construction of the next weld line must be removed;4.8 welds with multiple or multiple layers shall be smoothly welded a
24、nd their roughness shall be less than 1mm;4.9 requirements welding into the concave fillet weld, measures must be taken to make the weld metal and the parent material smooth transition, shall not leave a mark on its surface;4.10, after welding, remove the weld slag shell, the quality of the weld app
25、earance self-test, qualified after the welding mark, for self inspection, and then enter the next process;4.11 after work, turn off the power supply of all the equipment,The remaining welding wire and flux storage, inventory of various tools, clean up the work site, evacuate the work site.5, process
26、 factors5.1 welding wire caster angle: because of the role of the caster angle of the welding wire, the effect of the arc force on the metal in the back bath pool is weakened, and the liquid metal at the bottom of the bath pool is thickened and the melting depth is reduced. Because of the preheating
27、 effect, the melting width is increased;5.2 structural factors5.2.1 groove shape: when other conditions are equal, the groove depth and width are increased, and the weld penetration is increased slightly, the width of weld is decreased slightly, and the residual height and welding bonding ratio are
28、decreased remarkably;5.2.2 clearance: in the process, the group will be within a certain range of clearance, in order to prevent leakage of liquid metal;Web thickness: 6 16mm, clearance: 0 0.5mm;Web thickness: 2030 mum, gap: 0 1mm;The gap is too large, the leakage of liquid metal, weld molding is no
29、t good;5.2.3 workpiece thickness and workpiece heat dissipation conditionsWhen the penetration depth of H (0.7 0.8) t, then the plate thickness and the workpiece cooling condition has little influence on the penetration. But the heat dissipation condition of the workpiece has obvious influence on th
30、e width of weld and the remaining height. The weld width of the weld produced on the thick plate is smaller than that of the thin plate, but the remaining height is larger;5.3 environmental factors5.3.1 ordinary carbon structural steel thickness greater than 34mm, and high strength low alloy steel t
31、hickness greater than or equal to 30mm, should consider preheating; working place of not less than 0 degrees, the preheating temperature is controlled between 100 and 150 degrees; work place below 0 degrees, the preheating temperature should be set and test;5.3.2 preheating zone shall be in the rang
32、e of 80 to 100mm on both sides of the weld groove;6, special circumstances6.1, if it is found that the production plan, process specifications are inconsistent with the actual situation, or if there is any doubt about the semi-finished products transferred from the previous process, the relevant personnel should be promptly dealt with;6.2 in the welding process, if it is found that the quality problems can not be eliminated, the work should be stopped immediately and be dealt with by the personnel concerned.