挖掘机斗体与斗齿的焊接要领!

日期:2019-07-09   源头:http://www.sefibox.com/
  高温下为单相奥氏体布局,具有精良的韧性,由于外貌层在打击载荷下的加工硬化,具有较高的耐磨性。但这种钢的焊接性较差:起首,质料脆化是由于碳化物在焊接热影响区析出惹起的;二是焊缝的热裂纹,尤其是近焊缝地域的液化裂纹。
  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惹起脆化
  (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,大大飞扬了质料的韧性,告急粉碎了高锰钢的精良遵从。阐宣布明,当高锰钢再次加热并快速冷却时,碳化物起首在晶界析出。随着停顿时间的延伸,晶界处的碳化物由不延续的颗粒态革新为网状散布,脆性明白增长。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差异水平析出碳化物,并约莫转化为马氏体,不但使质料脆性增大,还飞扬了质料的耐磨性和打击韧性。并且,在热影响区温度范围(约650℃)停顿时间越长,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.
  为了淘汰碳化物的析出,防范质料失失韧性和脆性,应采取步伐加快其冷却速率,即在高温下紧缩停顿时间。为此,焊接要采取短焊、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
  防范热裂纹的要领是飞扬母材或焊接质猜中S和P的含量。也可以从焊接进程中采取步伐淘汰焊策应力,如采取短焊、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奥氏体钢作为隔绝焊道,防范裂纹。
  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)焊接前预备
  (1) Pre-welding preparation
  起首,将磨损的斗齿从斗体上取下,然后用角磨机将斗齿陈设打磨洁净,无污垢、锈迹,并过细查抄可否有裂纹等缺陷;斗齿焊接处采取碳弧气刨作坡口,用角磨机洗濯。
  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.
加长臂挖掘机出租
  (2)焊接
  (2) Welding
  (1)起首在桶体(和铲斗齿连合)GB e309-15焊条堆焊,焊条需要350℃,15 h单调,应该相对较大的焊接电流,焊接速率略慢,确保融合区镍含量5% ~ 6%,以防范裂纹的孕育发生敏感的马氏体。
  (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,焊缝长度不得超越跨过30mm。焊接后立刻水冷锻。
  (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。背焊采取直径32毫米的D266电极。低电流,直流反极性,断续焊接,短焊接。每次抑制焊策应及时水冷却,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,采取直径为4mm的D266电极举行间歇焊接,焊接电流为160A。一个电极需要3-4次完成。每次焊接抑制时,焊道运用水冷却至50℃以下,并锤击消弭应力,防范碳化物析出。完成两层焊接后,左右焊缝旋转焊接,包管焊接对称性,直至焊脚抵达16mm。每次焊接后,用增加镜查抄裂纹。要是有裂纹,焊接前用碳弧刨消弭。
  (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.
  颠末一年多的运用,斗齿的焊缝依旧精良。该要领遵从高,资源低,结果好,具有适用价钱。
  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.

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