What is E8018-B2 Electrode?
E8018-B2 is a low-hydrogen electrodes that produce weld metal that nominally contains between 1.00–1.50% chromium and 0.40–0.65% molybdenum. E8018-B2 is designed to produce weld metal for high-temperature service and for matching the properties of the typical Cr-Mo base metals usually known as 1 and 1 1/4 Cr-1/2 Mo steel (1.25Cr-0.5Mo) steel. E8018-B2 electrode coating type is basic iron powder.
E8018-B2 vs. E8018-B2L
E8018-B2 has a low carbon classification as E8018-B2L. While regular Cr-Mo electrodes produce weld metal with about 0.08% carbon, the “L-Grades” are limited to a maximum of 0.05% carbon. While the lower percent carbon in the weld metal will improve ductility and lower hardness, it will also reduce the high-temperature strength and creep resistance of the weld metal.
E8018-B2 electrode is supplied as per AWS A5.5 or ASME Section IIC, SFA 5.5. The equivalent of E8018-B2 as per EN or ISO standard according to EN 1599:1997 is E CrMo1 B 4 2 H5. The TIG equivalent wire of E8018-B2 is ER80S-B2 as per SFA 5.28. The meaning of E8018-B2 electrode is explained in below figure.
Chemical and mechanical properties of E8018-B2
The chemical and mechanical properties of E8018-B2 are shown in the below table. The tensile strength of E8018-B2 is 80 Ksi or 550 MPa and Yield strength is 67 Ksi or 460 MPa.
There is no toughness requirements for E8018-B2 electrode as the electrode is used for high temperature applications only while material toughness is a concerns in low temperature service conditions.
E8018-B2 electrode coating
E8018-B2 has basic coating and also called low hydrogen electrodes. Low-hydrogen electrodes have mineral coverings, which are high in calcium carbonate and other ingredients that are low in moisture and organic materials and hence “low in hydrogen content.” Low-hydrogen electrodes were developed for welding low-alloy, high-strength steels, some of which were high in carbon content.
Use of E8018-B2 Electrode
E8018-B2 electrode is used for welding of 1.25Cr-0.5Mo steels such as ASTM A335 Gr. P11, A387 Grade 11, A193 Gr. B7, A217 Gr. WC6.
The electrode is also used for the dissimilar welding of Cr-Mo steels such as 1.25Cr-0.5Mo to carbon steel or 0.5Mo to carbon steel material.
Storage and Baking/ conditioning of E8018-B2 electrode
E8018-B2 electrode being a low hydrogen electrode require electrode baking prior to use. Click here to learn about E8018-B2 electrode baking requirements.
E8018-B2 electrode polarity
Being a basic type electrode, E8018-B2 electrode is used with Direct current electrode positive (DCEP) and Alternating current (AC) polarity. DCEP gives a smooth arc and minimal spatters with optimized welding parameters.
DCEP also offers higher penetration and good appearance welds.
Welding parameters for E8018-B2
Typical value of current for E8018-B2 is shown in below table. 3/32 inch electrode requires generally 100 ampere and /8 inch runs well on 130-140 ampere range.