Question

identify the 8 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:

Identify the target digit

Using the AWS Electrode Classification knowledge point
The question asks to identify what the digit "8" represents in the AWS classification code E7018-1 H4R.

Analyze the AWS classification code

Using the AWS Electrode Classification knowledge point
Let's break down the components of the electrode classification E7018-1 H4R:

• E: Electrode
• 70: Minimum tensile strength in ksi (\(70,000\text{ psi}\))
• 1 (first digit after strength): Welding position
• 8 (second digit after strength): Type of coating and current
• -1: Indicates improved toughness (impact requirements)
• H4: Hydrogen level (less than \(4\text{ ml}/100\text{ g}\) of weld metal)
• R: Indicates requirements of absorbed moisture test (moisture resistant)

Answer:

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