Some standard content:
JB/T9185--1999
This standard is a revision of JB/Z261-86 Tungsten Inert Gas Welding Process Method. The original standard was slightly changed during the revision. The main differences are:
The writing method of this standard is in accordance with the current GB/T1.1 regulations: the scope of this standard is clarified;
The provisions on welding personnel responsibilities, welder training, safety, etc. in the original standard are removed. This standard replaces JB/Z261--86 from the date of implementation. Appendix A and Appendix B of this standard are both informative appendices. This standard is proposed and managed by the National Welding Standardization Technical Committee. The responsible drafting unit of this standard: Harbin Welding Research Institute. The main drafter of this standard: Tu Naiming.
This standard was first issued in 1986, and this revision is the first revision. 484
Standard of the Machinery Industry of the People's Republic of China
Welding Procedure Specification for Gas Tungsten Arc Welding1Fanyuan
This standard specifies the basic rules and requirements for the implementation of gas tungsten arc welding. JB/T 9185—1999
Replaces JB/Z261—86
This standard applies to tungsten inert gas welding of carbon steel, low alloy steel, stainless steel, aluminum and nickel-based alloys. 2 Reference Standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards will be revised, and the parties using this standard should explore the possibility of using the latest versions of the following standards. GB/T 985--1988 Basic forms and dimensions of weld grooves for gas welding, manual arc welding and gas shielded welding GB/T4191--1984 Tungsten-plated electrodes for inert gas shielded welding, plasma welding and cutting GB/T 4842--1995 Hydrogen GB/T 4844.1—1995 Industrial ammonia GB/T8110-1995 Carbon steel and low alloy steel welding wire for gas shielded arc welding GB/T9460—1988 Copper and steel alloy welding wire GB/T10858—1989 Aluminum and aluminum alloy welding wire YB/T5091--1996 Stainless steel rods and wires for inert gas shielded welding 3 Joint design and groove processing When the groove form and size of the weld are determined according to GB/T985, the following considerations should also be made. 3.1 Joint Design
When designing a joint, the first thing to consider is that the opening of the joint should allow the arc, pure shielding gas and filler metal to reach the bottom of the joint to ensure good accessibility. Factors affecting joint design include the chemical composition of the base metal, the thickness of the base metal, the required weld penetration depth and the characteristics of the welded metal (such as surface tension, fluidity, melting point, etc.). There are five basic joint types (see Figure 1) suitable for various metals. When there are special requirements, other reasonable joint types are allowed.
The general principles of groove design are as follows:
a) Butt joints of carbon steel, low alloy steel, stainless steel, aluminum with a thickness of not more than 3mm and high alloy with a thickness of not more than 2.5mm are generally not grooved.
b) For the above materials with a thickness of 3~~12mm, U-shaped, V-shaped or J-shaped grooves can be opened. c) For the above materials with a thickness greater than 12mm, it is better to use double-sided U-shaped or X-shaped grooves. d) The groove angle of the V-joint is about 60° for carbon steel, low alloy steel and stainless steel, and 80° for high nickel alloy steel. When welding aluminum with AC current, it is usually 90°. Typical joint dimensions for most metals are shown in Figure 2. Approved by Guohao Machinery Industry Bureau on June 24, 1999, implemented on January 1, 2000
JB/T9185—1999
Figure 1 Five basic joint types
a=3~12mm@=60°~90°b≤3mm;p≤2mmma) V-shaped groove
>12mm@=60°~90°b≤3mmp≤2mmb) X-shaped groove
Figure 2 Typical joint dimensions
e) The single-side side wall angle of the U-shaped groove is 7°~9° for carbon steel, low-alloy steel and stainless steel, about 15° for high-nickel alloy, and about 20°~30° for aluminum alloy.bzxz.net
f) The single-side groove angle of the T-shaped joint is about 45° for ferrous metals of different thicknesses, and as large as 60° for aluminum alloys. The typical groove dimensions of ferrous metals are shown in Figure 3. a) V-shaped
Typical groove dimensions of ferrous metals
b) X-shaped
c) Single-sided V-shaped
e) U-shaped
g) J-shaped
3.2 Groove processing methods
JB/T.9185—1999
Continued Figure 3
d) K-shaped
F) Double U-shaped
h) Double J-shaped
Groove processing is best done by turning for circular or circumferential grooves, and by milling or planing for longitudinal grooves. After cutting, the cutting fluid should be cleaned with solvent.
Note: The groove processing accuracy of automatic welding should be stricter than that of manual welding. 3.3 Groove cleaning
3.3.1 The groove should be cleaned within at least 20mm on each side. 3.3.2 The metal surface of the groove surface and the cleaned section shall not be left with harmful foreign matter such as oil, grease, paint, cutting fluid, marking pen, ink, moisture, processing chemicals, mechanical lubricants and oxides. 3.3.3 Dust, oil and grease can be scrubbed with volatile degreasing agents or non-toxic solvents. Paint and other materials that are insoluble in degreasing agents can be cleaned with chloroform, alkaline cleaning agents or special compounds. 3.3.4 There shall generally be no interlayer or other defects in the groove area. 3.3.5
Joint tack welding should be carried out according to the approved process. 3.3.6
Workpiece markings should be maintained for accurate recording. 4 Materials
4.1 Parent material
The parent material shall comply with the provisions of the relevant standards. When there are special requirements, they can be negotiated and resolved by the three parties of design, manufacturing and use. 447
JB/T9185—1999
Before welding, the chemical composition of the base metal must be known, which is an important basis for selecting filler metal, preheating, post-heating and other process parameters. When unexpected defects (such as insufficient penetration, a large number of pores and micro cracks, etc.) occur when the positive strip welding specification is adopted, it is necessary to find out the unknown trace elements that may exist in the base metal or welding materials. 4.2 Shielding gas
4.2.1 Type and quality of shielding gas
Hydrogen, nitrogen or hydrogen-ammonia mixed gas can be used as shielding gas. In special applications, hydrogen or nitrogen (about 5% each, limited to welding stainless steel, nickel-copper alloy and base alloy) can be added. Hydrogen for welding should comply with the provisions of GB/T4842. Nitrogen should comply with the provisions of GB/T4844.1. 4.2.2 Selection of shielding gas
See Table 1 and Table 2 for the selection and protection characteristics of shielding gas. The hydrogen flow rate is generally L/min; the nitrogen flow rate should be higher than that of hydrogen. Table 1 Selection of protective gas
Aluminum and its alloys
Inlaid alloys
Titanium and its alloys
Ar-He contains 75%He
Ar-Hz contains 15%Hz
Aluminum and magnesium
Welding types
Manual welding
Automatic welding
Shielding gas
Argon-nitrogen
Oxygen-nitrogen
Manual welding
Ar (AC, high frequency)
Ar, Ar-He
Ar, Ar-He
Ar, Ar-He
Protection characteristics of shielding gas
Shielding gas used
Automatic welding
Ar (AC, high frequency), He
Ar-He, He
Ar, Ar-Hz, Ar-He|| tt||Ar,He,Ar-He
Ar,Ar-He
The gas induction, purification and weld quality are good. Low gas consumption can increase welding speed
The weld quality is good, and the flow rate is lower than that of pure nitrogen (direct current positive connection)
Compared with hydrogen-nitrogen, the penetration depth is large and the welding speed is high
Stainless steel
Steel sugar and steel
Dart alloy
Silicon blue adjustment
Lead bronze
Welding type
Manual welding
Automatic welding
Manual welding
Automatic welding
4.3 Tungsten electrode
4.3.1 Types of tungsten electrode
a) Pure tungsten electrode,
Protective gas
Hydrogen-nitrogen
Hydrogen-hydrogen
(H2 not more than 35%)
Hydrogen-hydrogen-ammonia
Hydrogen-ammonia
b) Needle tungsten electrode (including oxidized needle);
c) Copper tungsten electrode (including oxidized steel);
d) Zirconium tungsten electrode (including oxidized aluminum):
JB/T 9185--1999
Table 2 (end)
Generally, it can extend the life of the electrode, the welding spot is better, the arc is easy to start, and it is easier to control the molten pool than nitrogen, especially in full-position welding, the welding speed is higher than hydrogen
When welding thin parts (≤2mm), the penetration depth can be controlled
When welding film parts, the penetration depth can be well controlled
The heat input is higher, and the welding speed may be higher for thicker parts to prevent undercutting. The required weld formation can be welded at low current, and the required flow rate is comfortable. The best choice for high-speed pipe welding operations
It can provide the highest heat input and deepest penetration. It is easy to control the molten pool, penetration and weld bead formation of thin parts. High heat input to compensate for the thermal conductivity of large thickness. The heat input is the largest when welding thick metal. Low flow can reduce the pollution of the metal flow and air to the weld and improve the performance of the heat affected zone. The penetration depth is large when manual welding of large thickness (shielding gas is required on the back to protect the back wall from pollution). Reduce the crack tendency of this "hot brittle" metal. The penetration depth of the parent material is shallow. e) Tungsten electrode (including tungsten oxide) should comply with the provisions of GB/T4191. 4.3.2 Tungsten electrode current carrying capacity. The size of the tungsten electrode current carrying capacity is mainly affected by the tungsten electrode diameter. Table 3 lists the recommended current range according to the electrode diameter. The welding current shall not exceed the upper limit of the current carrying capacity specified in the tungsten electrode product manual. Table 3 Recommended current range according to electrode diameter
Electrode diameter
Electrode is negative (-)
With oxide
2~20
40~130
75~180
60~150
100~200
Electrode is positive (+)
Tungsten with oxide
45~90
65~125
Tungsten with oxide
60~125
85~160
Electrode diameter
Electrode is negative (-)
Tungsten with oxide added
130~230
160~310
275450
400~625
550675
170~250
225~330
350~480
500~675
650~950
4.3.3 Tungsten terminal head geometry and processing
The commonly used tungsten terminal head shape is shown in Figure 4. Small current
JB/T 9185—1999
Table 3 (end)
Electrode is positive (+)
50~70
65~100
Large current
Tungsten with added compounds
17~30
20~35
50~70
65~100
Figure 4 Commonly used tungsten tip shapes
80~140
150~~190||tt| |180~260
240～350
300-450
Chromium with oxide added
120~210
150--250
240350
330460
430575
650~830
AC current
The tungsten electrode should be ground with a special hard abrasive grinding wheel, and the uniformity of the tungsten electrode geometry should be maintained. When grinding the needle and tungsten electrode, a sealed or exhaust-type grinding wheel should be used. After grinding, the worker should wash his hands and face. 4.4 Filler metal
The filler metal used in tungsten inert gas shielded welding can generally be similar to the chemical composition of the base material. However, from the perspective of corrosion resistance, strength and surface shape, the composition of the filler metal may be different from that of the parent material. The selected filler metal shall comply with the following corresponding provisions: a) Carbon steel and low alloy steel welding wires shall comply with the provisions of GB/T8110; b) Stainless steel welding wires shall comply with the provisions of YB/T5091; c) Steel and copper alloy welding wires shall comply with the provisions of GB/T9460: d) Aluminum and aluminum alloy welding wires shall comply with the provisions of GB/T10858; e) In the absence of corresponding standards, it can be agreed upon by both the supplier and the buyer. The filler metal should be stored in a clean and dry warehouse. 5 Principles for the selection of main welding process meals
After the above materials are determined, the process parameters should be determined through process tests and process assessments. The welding process parameters can be found in Appendix A (Suggested Appendix) and Appendix B (Suggested Appendix). 5.1 Arc starting method
According to production conditions and requirements, the following arc starting methods can be selected: a) Short circuit arc starting, arc starting plate is required;
JB/T9185—1999
b) High frequency arc starting: with the help of high cheek generator. For manual welding and automatic welding, it can be used when using direct current or alternating current. c) Pulse arc starting: a high voltage is added between the electrode and the workpiece to cause ionization in an instant; d) Induction arc starting: used for spot welding.
5.2 Welding current
There are three types of welding currents, and the applicable scope of various currents is as follows: a) AC current: welding aluminum, magnesium and its alloys, welding copper with oxide film; b) DC current: positive polarity DC current can weld almost all ferrous metals. Reverse polarity DC current is rarely used; c) Program current (current pulse technology): can control and improve the welding root and weld bead forming, improve the penetration depth and grain size and special position welding.
5.3 Arc voltage
Arc voltage refers to the voltage drop between the tip of the tungsten electrode and the workpiece, and its magnitude is mainly affected by the type of welding current and the shielding gas used. Under the same arc gap, nitrogen can produce a larger voltage drop than hydrogen. The difference between the two is about 4V. Therefore, using nitrogen protection can achieve a deeper penetration.
The geometry of the electrode tip also affects the magnitude of the arc voltage. Under the condition of the same distance from the tungsten electrode tip to the workpiece, the arc voltage of the sharper conical electrode is higher.
The arc voltage control method can be selected according to the specific product and power supply type, but the arc voltage should be controlled to remain relatively stable. 5.4 Welding speed
The arc penetration depth is usually inversely proportional to the welding speed. The thermal conductivity of the metal, the thickness and size of the component are the main considerations for controlling the welding speed. The purpose of changing the welding speed is to maintain a constant heat required for constant arc penetration. The welding speed should generally follow the following principles: a) When welding high thermal conductivity metals such as aluminum, in order to reduce deformation, a welding speed faster than the thermal conductivity of the base material should be used; b) High-speed welding cannot be used for welding alloys with a tendency to thermal cracking; c) The size of the weld pool is directly affected by the welding speed. When welding in a non-flat position, only a smaller weld pool can be formed, and the welding speed should be appropriately increased;
d) The development of welding current pulse control technology is very beneficial to the control of the joint weld pool when welding low thermal conductivity metals (such as titanium) and fixed pipes and thick-walled pipes.
5.5 Wire feeding methods
According to production conditions, there are three types of wire feeding methods:
a) manual feeding by welders;
b) automatic feeding by wire feeders;
c) pre-filling metal before welding.
6 Quality inspection
The surface of tungsten inert gas shielded welds is generally not trimmed and can be inspected directly. a) Visual inspection, all factors affecting quality should be checked, such as groove processing, groove cleaning and assembly, as well as the visible conditions of the entire weld surface, weld size, penetration, surface pores, undercuts and cracks, etc.; b) Other commonly used inspection methods are liquid penetration method, magnetic particle method, ultrasonic method, eddy current method and radiographic method. The selection method depends on the requirements for product quality level;
c) The inspection procedure must have inspection process and acceptance standards to ensure product quality. 451
Material thickness
Joint design
Electrode strength and voltage
Welding speed
Electrode type
Electrode size
Filling metal type
Filling metal size
Shielding gas
Gas flow
Back gas flow
Nozzle size
Nozzle to workpiece height
Preheating temperature (minimum)
Interpass temperature
Post weld heat treatment
Welding position
dm/min
dm'/min
JB/T 9185-1999
Appendix A
(Suggestive Appendix)
Recommended stainless steel welding process parameters
Straight edge butt
>3.0~6. 0
V-shaped groove
70~120
DC positive polarity
According to technical requirements
Needle tungsten electrode
18-8 type
Horizontal vertical
>6.0～12
X-shaped groove
100~150
Material thickness
Joint design
Arc voltage
Welding speed
Tungsten electrode type
Electrode size
Filling Metal type
Filling metal size
Shielding gas
Shielding gas flow
Back shielding gas flow
Nozzle size
Nozzle to workpiece distance
Preheat overflow (minimum)
Interpass temperature (maximum)
Post weld heat treatment
Explosion joint position
dm'/min
dm'/min
JB/T9185--1999
Appendix B
(Appendix of tips)
Recommended carbon steel welding process parameters
Straight edge butt
50~100
>3.0～6.0
V-shaped slit
70~120
DC positive polarity
According to technical requirements
Needle tungsten electrode
According to technical requirements
Horizontal, vertical and horizontal
2.5～3.2
X-shaped slit
90~150
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