The single phase austenite structure at high temperature has good toughness, and the surface layer has high wear resistance due to work hardening under impact load. But the weldability of this kind of steel is poor: firstly, the material embrittlement is caused by the precipitation of carbide in the heat affected zone of welding; secondly, the hot crack in the weld, especially the liquefaction crack near the weld.

　　(1)热影响区析出的碳化物引起脆化

　　(1) Brittleness due to carbides precipitated from heat-affected zone

　　ZGMn13高锰钢在250℃以上再次加热时，会沿晶界析出碳化物，大大降低了材料的韧性，严重破坏了高锰钢的性能。分析表明，当高锰钢再次加热并快速冷却时，碳化物在晶界析出。随着停留时间的延长，晶界处的碳化物由不连续的颗粒态转变为网状分布，脆性显著增加。因此，当高锰钢焊接或焊接后再加热时，在焊接热影响区某一段会不同程度析出碳化物，并可能转化为马氏体，不仅使材料脆性增大，还降低了材料的耐磨性和冲击韧性。而且，在热影响区温度范围(约650℃)停留时间越长，析出的碳化物越多。

　　When ZGMn13 high manganese steel is reheated above 250 C, carbides will precipitate along the grain boundary, which greatly reduces the toughness of the material and seriously damages the excellent properties of high manganese steel. The analysis shows that carbides precipitate at grain boundaries first when the high manganese steel is reheated and cooled rapidly. With the increase of residence time, the carbides at grain boundaries change from discontinuous granular state to network distribution, and the brittleness increases significantly. Therefore, when high manganese steel is welded or reheated after welding, carbides will precipitate to varying degrees in a certain section of the welding heat affected zone and may be transformed into martensite, which not only increases the brittleness of the material, but also reduces the wear resistance and impact toughness of the material. Moreover, the longer the residence time in the temperature range of HAZ (about 650 C), the more carbides precipitated.

　　为了减少碳化物的析出，防止材料失去韧性和脆性，应采取措施加快其冷却速度，即在高温下缩短停留时间。为此，焊接要采用短焊、间歇焊、水浴焊。

　　In order to reduce the precipitation of carbides and prevent materials from losing toughness and brittleness, measures should be taken to accelerate the cooling rate, that is, to shorten the residence time at high temperature. For this reason, short welding, intermittent welding and water bath welding should be adopted.

　　(2)焊接热裂纹

　　(2) Welding Hot Crack

　　防止热裂纹的方法是降低母材或焊接材料中S和P的含量。也可以从焊接过程中采取措施减少焊接应力，如采用短焊、断续焊、散焊和焊接锤等。当高锰钢堆焊在筒体上时，可以焊接一层cr-ni、cr-ni-mn或cr-mn奥氏体钢作为隔离焊道，防止裂纹。

　　The way to prevent hot cracking is to reduce the content of S and P in base metal or welding material. Measures can also be taken to reduce welding stress from the welding process, such as short welding, intermittent welding, scatter welding and welding hammer. When the high manganese steel is surfacing on the cylinder, a layer of cr-ni, cr-ni-mn or Cr-Mn austenitic steel can be welded as isolation weld to prevent cracks.

　　2. 斗体与齿的焊接工艺

　　2. Welding Technology of Bucket Body and Teeth

　　(1)焊接前准备

　　(1) Pre-welding preparation

　　，将磨损的斗齿从斗体上取下，然后用角磨机将斗齿安装打磨干净，无污垢、锈迹，并仔细检查是否有裂纹等缺陷;斗齿焊接处采用碳弧气刨作坡口，用角磨机清洗。

　　Firstly, the worn bucket teeth are removed from the bucket body, and then the bucket teeth are installed and polished with angle mill, without dirt and rust, and the defects such as cracks are carefully checked. Carbon arc air gouging is used as groove in the welding of the bucket teeth, and the bucket teeth are cleaned with angle mill.

　　(2)焊接

　　(2) Welding

　　(1)在桶体(和铲斗齿联合)GB e309-15焊条堆焊,焊条需要350℃,15 h干燥,应该相对较大的焊接电流,焊接速度略慢,确保融合区镍含量5% ~ 6%,以防止裂纹的产生敏感的马氏体。

　　(1) First of all, in the barrel body (combined with bucket teeth) GB e309-15 electrode surfacing, the electrode needs 350 C, 15 h drying, should be relatively large welding current, welding speed is slightly slow, to ensure that the fusion zone nickel content of 5%-6%, in order to prevent the formation of cracks sensitive martensite.

　　(2)焊接位置。斗齿就位后，用直径为32mm的D266焊条两侧对称定位焊接，焊缝长度不得超过30mm。焊接后立即水冷锻。

　　(2) Welding position. After the bucket teeth are in place, symmetrically positioned welding is carried out on both sides of D266 electrode with a diameter of 32 mm. The length of the weld shall not exceed 30 mm. Water-cooled forging immediately after welding.

　　(3)打底焊。背焊采用直径32毫米的D266电极。低电流，直流反极性，断续焊接，短焊接。每次停止焊接应及时水冷却，层间温度控制在50℃以下。

　　(3) Back welding. The D266 electrode with a diameter of 32 mm is used for back welding. Low current, DC reverse polarity, intermittent welding, short welding. Every time the welding stops, the water should be cooled in time, and the interlayer temperature should be controlled below 50 C.

　　(4)填满焊。底部焊接后，采用直径为4mm的D266电极进行间歇焊接，焊接电流为160A。一个电极需要3-4次完成。每次焊接停止时，焊道应用水冷却50℃以下，并锤击应力，防止碳化物析出。完成两层焊接后，左右焊缝旋转焊接，保证焊接对称性，直焊脚达到16mm。每次焊接后，用放大镜检查裂纹。如果有裂纹，焊接前用碳弧刨。

　　(4) filling welding. After bottom welding, D266 electrode with diameter of 4 mm was used for intermittent welding, and the welding current was 160A. One electrode needs to be completed 3-4 times. When each welding stops, the bead should be cooled to below 50 C by water, and the stress should be eliminated by hammering to prevent carbide precipitation. After two layers of welding are completed, the left and right seams are rotated to ensure the symmetry of the welding until the welding foot reaches 16 mm. After each welding, check the cracks with a magnifying glass. If there is a crack, use carbon arc planer to eliminate it before welding.

　　经过一年多的使用，斗齿的焊缝仍然良好。该方法效率高，成本低，效果好，具有实用价值。

　　After more than a year of use, the weld of bucket teeth is still good. The method has high efficiency, low cost, good effect and practical value.