The bucket material of excavator has good weldability. The bucket tooth material is high manganese steel. It has single phase austenite structure at high temperature. It has good toughness and high wear resistance under impact load due to surface hardening. Next let's look at the welding process of bucket body and bucket teeth.
1. Pre-welding preparation. Firstly, the worn bucket teeth are removed from the bucket body, and then the installation bucket teeth are polished with a corner mill. No dirt, rust and cracks are allowed. Carbon arc air gouging is used to open the groove at the welding place of the bucket teeth, and the angle mill is used to clean up the groove.
Firstly, GBE309-15 electrode is used for surfacing on the bucket body (the joint with bucket teeth). Before welding, the electrode needs to be dried at 350 C and 15 H. The welding current should be too high and the welding speed should be slightly slow to ensure the nickel content in the fusion zone of 5%-6% and prevent the formation of crack-sensitive martensite.
(2) Position welding. After the bucket teeth are assembled in place, symmetrical positioning welding is carried out on both sides with D266 electrode with a diameter of 32 mm. The length of the weld seam is not more than 30 mm. Water cooling and hammering immediately after welding.
Back welding. D266 electrode with a diameter of 32 mm was used for bottom welding. Low current, DC reverse polarity, intermittent welding and short segment welding are used. Water cooling should be done in time during each stop, and the interlayer temperature should be controlled below 50 C.
(4) Filling welding. After the bottom welding is completed, D266 electrode with diameter of 4 mm is used for intermittent welding. The welding current is 160A, and one electrode is welded in three to four times. When each welding stop is completed, water should be used to cool the weld bead below 50 C in time, and hammering is carried out to eliminate stress and prevent carbide precipitation. After each two layers of welding, the left and right seams are alternately welded to ensure the symmetry of the welding until the welding foot reaches 16 mm. 。 The cracks are checked with a magnifying glass after each welding. If there are cracks, the cracks are eliminated by carbon arc air gouging before welding.
After repairing bucket teeth by this method, the weld seam is still good after more than one year's use. This method has high efficiency, low cost and good effect in repairing bucket teeth, and has certain practical value.
Huangzuan Machinery established in 2008, is a specialized manufacturer of bucket teeth, bucket adaptor and side cutter which is used Caterpillar, Komatsu, Hyundai, Daewoo, Kobelco, Hensley, Liugong, Hitachi, XCMG, XGMA, Volvo, Esco, JCB .etc.