The hot welding repair technology of diesel engine is as follows:
Hot welding process of 1 diesel engine cast iron
The so-called hot welding is to preheat the workpiece to 650~700 C before welding, and keep it welding at this temperature. It is slow and cold after welding. The welding stress is small, it is not easy to produce white mouth and crack, which is easy to machine. The disadvantage is that the equipment is complicated and the welding cost is high, and it is generally used only in the key parts of strength.
Enhanced welding repair technology for 2 diesel engine cast iron
It is on the basis of cold welding, in order to meet the requirements of the strength of the weldment, in order to meet the requirements of the strength of the weldment. It has solved the defects of low strength and poor crack resistance in the cold welding of cast iron to some extent. It has been thrown to repair castings with broken castings and high thickness and high weld strength. The reinforced component can be high out of the surface of the part and can be welded with ordinary high quality low carbon steel electrode. Otherwise, the strengthening element should be lower than the surface of the part. If the machine is to be processed, it is also needed to be welded with a cast iron electrode. The strengthening element is usually made of low carbon steel. According to the working requirements of the parts, the strengthening measures are selected.
(1) the method of silk planting.
Drilling and tapping near the defect (no oil can be used to plant a certain number of studs and then welding. The diameter of the stud should be adapted to the thickness of the part; the depth of the screw should be 1.5 times the diameter of the stud; the sum of the cross section of the stud should not exceed 25% of the total area of the groove, and the single surface can be welded. The high metal is not allowed after the workpiece is welded. " When the surface is out of the surface, the groove on both sides of the slope is determined by the thickness of the workpiece, but it must not be less than 3 millimeters. When the deposited metal is high out of the surface of the part, the groove can be V shaped or X shaped. The distribution of the stud can be arranged in a staggered arrangement and distributed evenly on both sides of the crack.
(2) Gala tendons.
It can be carried out at the same time as a double row of silk or plum blossom, that is, to connect the stud on both sides of the crack with a stretch of tendons. Usually, the stud of the stud is properly lengthened, the red is bent, and the head is welded. Sometimes, the welding repair and the stretch are carried out respectively, such as when the rear axle housing of the East Red 802 tractor is broken with the diaphragm connection, it can be facing the front plane of the shell. The position of the clapboard (above drilling and tapping, tighten the diaphragm with the M10 countersink inner screw, then weld the cracks).
(3) metal buckle.
First, the metal buckle is selected according to the work piece, and then the metal clasp hole is processed. It requires 0.02 to 0.05 millimeter matching tightness. The metal buckle is left with gap. When the wall thickness is more than 50 millimeters, if the crack has penetrated, the metal buckle can be inlaid in the middle and welding on both sides.
(4) the main points of welding.
In addition to the cold welding process of cast iron, when the groove is not opened, the ring welding is carried out at the connecting place of the tendon and the silk, then the cracks are welded on both sides of the tendon, and the cracks are welded at the end. In the opening groove, the planting silk and the drawing, the circular welding skin is used to weld the stud or the tendon in continuous welding, and the subsection reverse welding is used to weld the non welded joints between the stretch groups. The second layer section converse. The welding should be perpendicular to the first layer until the groove is filled. When welding, the stud and the stretch should be deposited with the base metal and sink the metal. When the metal buckle is inserted, the end of the metal buckle is welded first, then the other end is welded, then the weld is welded and the crack is welded. In order to improve the welding performance and prevent the crack, the welding process can be used in the welding process. In addition, the proper placement of some waste electrodes in the molten pool can melt more metals in a relatively short time, not only reduce the temperature of the weld pool and weldment, save the electrode, but also improve the chemical composition and properties of the weld metal, so as to obtain better welding quality.
