Covered Electrodes For Nickel Alloy

Introduction to nickel-based alloy steel electrodesselectrodess-coated electrodes

 

1.Suggestions for welding material selection:

  The selection of nickel-based welding materials mainly depends on the alloy composition of base metal, the application properties of workpieces, the design type of workpieces, working temperature, environmental corrosion and other factors to select suitable welding materials and welding methods.

 

  According to the classification of specifications and class numbers of AWS A5.11 "Code for Arc Welding of Nickel and Nickel Alloy Shielded Metals", the classification is based on the main components of dissolved gold. The information of tensile strength grade will not be displayed on the specifications. The welding current of such materials is mostly DC (+) design, and a small part 

 

Specification Class Number

Characteristic or application

ENi1

Pure nickel forgings or castings are welded or coated as different materials, which are commonly used in chemical industry, food and medical equipment.

ENiCr-4

It is usually used in corrosive environment of burning heavy oil and has high temperature rust resistance.

ENiCu-7

It is used for welding Ni-Cu alloy and steel with different materials or steel side coating.

ENiCrFe-X系列

It can be used in ultra-low temperature to high temperature (480 ~ 980 ℃) environment, ENiCrFe-1/-2/-3 is usually used in high temperature environment, and ENiCrFe-4/-9/-10 is used for welding 9% Ni steel.

ENiCrFeSi-X系列

The Si content is about 2.8%, which is generally used for welding ASTM B163, B166, B167, B168 and other steel grades.

ENiMo-X系列

It is used for welding Ni-Mo alloy and steel with different materials or steel side coating. ENiMo-8/-9 is used for welding 9% Ni steel.

ENiCrMo-X系列

It is used for welding Ni-Cr-Mo alloy and steel with different materials or steel side coating, ENiiCrMo-3/-4/-6 is used for welding 9% Ni steel, and the rest is mostly used for equipment in high temperature and high corrosion environment.

ENiiCrCoMo-1

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 ℃.

ENiCrWMo-1

ASTM B366, B435, B564, B572 steel grade welding, this welding material is usually used in flat welding position

 

 

 

2.Key points of welding operation:

(1)Storage management of welding rod


①The welding rod shall be stored in a relatively dry warehouse to avoid excessive moisture absorption caused by the simultaneous existence of high humidity (≥ 80% R.H) and high heat (≥ 30 ℃).

 

Before use, it must be dried at high temperature and placed in a heat preservation barrel or low-temperature oven on the construction site. It shall be stored at 100 ~ 150 ℃. A small amount of it shall be taken each time to reduce the moisture content of the weld and avoid the problem of weld channel pores. Please refer to the instructions in the appendix for drying conditions.

 

 

(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.

 

The core wires of nickel-based coated electrodess are all made of nickel alloy, with slow heat conduction speed and high expansion coefficient. Therefore, excessive welding current will cause the resistance heat of the core wires to become higher, causing the coated electrodes to generate red heat and fall off.

 

③The fluidity of molten iron in nickel-based alloy is poor. For example, if the rod is transported by weaving, the weaving amplitude should be less than 3 times of the rod diameter; It is also necessary to avoid the phenomenon of hot cracking of electrodes caused by excessive heat input, especially at the position of finishing pit

 

④The arc starting point of butt slotting welding is recommended to move the arc to the position of the welding starting point after arc starting is done on the slotting surface; It is suggested to stop the filler at the finishing pit before breaking the arc, so as to avoid excessive cracking of the pit; The finishing pit of the previous electrodes must be ground clean to avoid cracking, slag inclusion, air holes and other problems.

 

Short arc welding shall be maintained to avoid air holes caused by water vapor and nitrogen dissolving into the welding channel; The arc force is usually weak, so attention should be paid to the matching of arc and molten iron flow to avoid poor dissolution or slag inclusion.

 

 The arc starting method shall be handled by the "forward and backward method", i.e. the arc starting point shall be located about 1 ~ 2cm after the welding point. After arc starting, the "forward method" shall be used to bring the arc forward to the welding point for welding operation, so as to eliminate the air hole problem at the welding point.

 

There is no need to preheat during welding, and the temperature between tracks is suggested ≤ 150 ℃.

 

 Welding slag is usually thick and needs to be cleaned to avoid slag inclusion. Steel wire brushes must be made of stainless steel and avoid sharing with other materials.

 

View:

SNM-6

鎳合金SMAW銲接
AWS A5.11 ENiCrMo-6
JIS --
EN ISO 14172 E Ni 6620
GB T13814 ENi6620

SNM-4

鎳合金SMAW銲接
AWS A5.11 ENiCrMo-4
JIS Z3224 ENi6276
EN ISO 14172 E Ni 6276
GB T13814 ENiCrMo-4

SNM-3

鎳合金SMAW銲接
AWS A5.11 ENiCrMo-3
JIS Z3224 ENi6625
EN ISO 14172 E Ni 6625
GB T13814 ENiCrMo-3

SNF-3

鎳合金SMAW銲接
AWS A5.11 ENiCrFe-3
JIS Z3224 ENi6182
EN ISO 14172 E Ni 6182
GB T13814 ENiCrFe-3

SNF-2

鎳合金SMAW銲接
AWS A5.11 ENiCrFe-2
JIS Z3224 ENi6133
EN ISO 14172 E Ni 6092
GB T13814 ENiCrFe-2

SNF-1

鎳合金SMAW銲接
AWS A5.11 ENiCrFe-1
JIS Z3224 ENi6062
EN ISO 14172 E Ni 6062
GB T13814 ENiCrFe-1