Introduction of nickel-based alloy steel welding materials—flux-coated welding wire
1.Suggestions for welding material selection：
According to the specification category number classification of AWS A5.34 "Code for Arc Welding of Nickel and Nickel Alloy Charged Welding Wire", the classification is based on the main components of dissolved gold, welding posture and shielding gas. The information of tensile strength grade will not be displayed on the specification. The welding current of such materials is DC (+). The relevant classification and application are summarized as follows：
|
Specification Class Number |
Shielding gas |
Welding position |
|
ENiXXXXT0-1 |
100%CO2 |
Flat Welding (F), Horizontal Fillet Welding (H-Fillet) |
|
ENiXXXXT1-1 |
100%CO2 |
Full posture |
|
ENiXXXXT0-3 |
-- |
Flat Welding (F), Horizontal Fillet Welding (H-Fillet) |
|
ENiXXXXT0-4 |
75~80%Ar + 20~25%CO2 |
Flat Welding (F), Horizontal Fillet Welding (H-Fillet) |
|
ENiXXXXT1-4 |
75~80%Ar + 20~25%CO2 |
Full posture |
Classification is made according to component
content, and its related application is as follows：
|
Principal component category |
Specification Class Number |
Characteristic or application |
|
Nickel-chromium |
ENiCr3Tx-y |
It is used for welding Ni-Cr-Fe alloy or steel side coating welding when welding with different materials of steel. It is generally welded with ASTM B163, B166, B167, B168 and other steel grades. |
|
Nickel-chromium-iron |
ENiCrFe1Tx-y |
Same as above. |
|
ENiCrFe2Tx-y |
It has better crack resistance than ENiCrFe1Tx-y, and is used for welding Ni-Cr-Fe alloy, or side coating welding of steel when welding with different materials of steel, 9Ni steel, or welding with different materials of other steel grades. |
|
|
ENiCrFe3Tx-y |
The crack resistance is the best welding material in NiCrFe series, which is used for welding Ni-Cr-Fe alloy or Ni-Cr alloy, or welding with different materials of other steel grades. |
|
|
Nickel-chromium-molybdenum |
ENiCrMo2Tx-y |
It is used for welding Ni-Cr-Mo alloy or welding with different materials of steel. It is generally welded with ASTM B435, B572, B619, B622, B626 and other steel grades. |
|
ENiCrMo3Tx-y |
Used for welding nickel-chromium-molybdenum alloy or nickel-iron-molybdenum alloy, generally welded with ASTM B443, B444, B446, B407, B409, B5l4, B564 and other steel grades. |
|
|
ENiCrMo4Tx-y |
Used for low carbon Ni-Cr-Mo alloy welding, generally with ASTM B574, B575, B619, B622, B626 and other steel grades welding. |
|
|
ENiCrMo10Tx-y |
Used for welding nickel-chromium-molybdenum alloy, generally with ASTM B574, B575, B619, B622, B626 and other steel grades. |
|
|
Nickel-chromium-cobalt-molybdenum |
ENiCrCoMo1Tx-y |
It is used for welding Ni-Cr-Co-Mo alloy and
steel with different materials or steel side coating, and has high temperature
strength and oxidation resistance in high temperature environment of 820 ~ 1150
℃. |
|
Nickel-molybdenum |
ENiMo13-Tx-y |
It is commonly used for welding 9Ni steel, and
is generally welded with ASTM A333, A334, A353, A522, A553 and other steel
grades. |
2.Key points of welding operation：
(1) Storage management of welding wire：
Please refer to the description of carbon steel welding wire for storage management.
(2)Precautions for welding：
①Before operation, clean treatment shall be carried out at the welding part and the workpiece part within 50mm around it to avoid cracks or pores caused by weld pollution.
② In general use, 75 ~ 80% Ar + 20 ~ 25% CO2 mixture is recommended as protective gas to form an arc mode of spray arc migration, and the gas flow rate is set at 20 ~ 25 l/min.
③The oxide layer or residue on the weld surface shall be removed with special grinding wheel and stainless steel brush.
④ It is suggested to stop the filler at the final melting pit before breaking the arc to avoid cracking of the welding channel melting pit.
⑤ There is no need to preheat during welding, and the temperature between tracks is suggested ≤ 150 ℃
