Question
Identify the H4 in the AWS classification for mild steel electrodes.
Hydrogen level in ml/100 g
Welding position
Minimum tensile strength in KSI
Indicates impact requirements
Electrode
Type of coating and current
Indicates requirements of absorbed moisture test
E7018-1 H4R
Hydrogen level in ml/100 g
Welding position
Minimum tensile strength in KSI
Indicates impact requirements
Electrode
Type of coating and current
Indicates requirements of absorbed moisture test
E7018-1 H4R
Answers
Answered by
GPT-4o mini
In the AWS (American Welding Society) classification for mild steel electrodes such as E7018-1 H4R, the code can be broken down as follows:
- **E**: Indicates that the electrode is suitable for electric arc welding.
- **70**: The minimum tensile strength of the weld metal is 70,000 psi (pound-force per square inch), which is equivalent to 70 KSI (Kilo Pounds per Square Inch).
- **1**: Indicates that the electrode is suitable for use in all positions (flat, horizontal, vertical, and overhead).
- **H4**: Refers to the maximum hydrogen level in the weld deposit, which is 4 ml of hydrogen per 100 grams of the weld metal. This is important for preventing hydrogen-induced cracking in the weld.
- **R**: Indicates that the electrode has been designed to meet the requirements for higher atmospheric moisture absorption and includes specific requirements for absorbed moisture tests, making it suitable for applications requiring high-impact toughness.
### Summary of E7018-1 H4R:
- **Hydrogen Level**: H4 - Maximum 4 ml of hydrogen per 100 g
- **Welding Position**: 1 - All positions
- **Minimum Tensile Strength**: 70 KSI
- **Indicates Impact Requirements**: The "1" designation suggests suitability for impact requirements and the "R" indicates it's designed for high toughness.
- **Electrode**: E7018-1 H4R
- **Type of Coating and Current**: Low hydrogen, typically compatible with both AC and DC (electrode will typically be used with DC+ polarity).
- **Indicates Requirements of Absorbed Moisture Test**: The "R" indicates adherence to requirements for moisture absorption testing.
This classification helps welders choose the right electrode for their specific welding applications, especially in terms of strength, position, and toughness under impact conditions.
- **E**: Indicates that the electrode is suitable for electric arc welding.
- **70**: The minimum tensile strength of the weld metal is 70,000 psi (pound-force per square inch), which is equivalent to 70 KSI (Kilo Pounds per Square Inch).
- **1**: Indicates that the electrode is suitable for use in all positions (flat, horizontal, vertical, and overhead).
- **H4**: Refers to the maximum hydrogen level in the weld deposit, which is 4 ml of hydrogen per 100 grams of the weld metal. This is important for preventing hydrogen-induced cracking in the weld.
- **R**: Indicates that the electrode has been designed to meet the requirements for higher atmospheric moisture absorption and includes specific requirements for absorbed moisture tests, making it suitable for applications requiring high-impact toughness.
### Summary of E7018-1 H4R:
- **Hydrogen Level**: H4 - Maximum 4 ml of hydrogen per 100 g
- **Welding Position**: 1 - All positions
- **Minimum Tensile Strength**: 70 KSI
- **Indicates Impact Requirements**: The "1" designation suggests suitability for impact requirements and the "R" indicates it's designed for high toughness.
- **Electrode**: E7018-1 H4R
- **Type of Coating and Current**: Low hydrogen, typically compatible with both AC and DC (electrode will typically be used with DC+ polarity).
- **Indicates Requirements of Absorbed Moisture Test**: The "R" indicates adherence to requirements for moisture absorption testing.
This classification helps welders choose the right electrode for their specific welding applications, especially in terms of strength, position, and toughness under impact conditions.