Final answer:
The correct electrode for all position welding with severe impact requirements is typically an E7018 electrode. However, based on the given options, E6218-BL3 appears to be the most similar and suitable for high impact and low-temperature conditions.
Step-by-step explanation:
The electrode used for all position welding with severe impact requirements is E7018. This classification of electrode is known for its low hydrogen coating and is capable of providing high-quality welds with good toughness at temperatures as low as negative 50 degrees Fahrenheit. It is often used in welding structures where high stress and impacts are expected, like bridges or industrial equipment. None of the options provided exactly match the renowned E7018, but option c) E6218-BL3 seems to be a variation of it, designed for those types of applications. The correct electrode option for all position welding with severe impact requirements is E4918-1. This electrode is specifically designed for high-strength, low-alloy steels, making it suitable for applications that require high impact resistance.