Question

identify the 1 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

Explanation:

Analyze the AWS electrode classification system

Using the AWS Electrode Classification knowledge point

• E: Stands for electrode.
• 70: Indicates the minimum tensile strength of the weld metal in KSI (70,000 psi).
• 1: Indicates the welding position. A "1" means the electrode can be used in all positions (flat, horizontal, vertical, and overhead).
• 8: Indicates the type of coating and welding current (low-hydrogen potassium, AC or DCEP).
• -1: Indicates improved toughness (impact requirements).
• H4: Indicates diffusible hydrogen limits (less than 4 ml/100 g of weld metal).
• R: Indicates moisture resistance requirements.

Identify the specific digit

Using the AWS Electrode Classification knowledge point

• The question asks to identify the boxed digit "1" in the classification "E7018-1 H4R".
• Based on the classification rules, this digit represents the welding position.

Answer:

• Hydrogen level in ml/100 g
• Welding position (Correct answer)
• Minimum tensile strength in KSI
• Indicates impact requirements
• Electrode
• Type of coating and current
• Indicates requirements of absorbed moisture test