A36 SMAW (low-hydrogen) 예열 — 3/4" to 1-1/2"

SMAW (Low-Hydrogen)

Low-hydrogen SMAW (E7018/E7016) uses basic-coated electrodes requiring rod oven storage, assigned to Category B in Table 5.11.

E7018 is the default electrode for structural fillet and groove welds on common building steels. Rod ovens should hold at a minimum of 250°F per D1.1 Clause 7.3.2.1; exposure time out of the oven is limited to 4 hours maximum per Table 7.1. For overhead position, use 3/32" diameter rods to control puddle size. Vertical-up stringer beads provide the best fusion on thicker members.

A36

ASTM A36 is the most commonly specified structural steel in North America, with a minimum yield strength of 36 ksi and 58-80 ksi tensile range. It appears in both Category A (non-low-hydrogen SMAW) and Category B (low-hydrogen processes) of Table 5.11. A36 is available as plate (up to 8" thick), W-shapes, channels, angles, and bars from virtually every domestic mill. Its moderate carbon content (0.26% max for shapes, 0.25% max for plate up to 3/4") and typical carbon equivalent of 0.35-0.42 give it good weldability across all prequalified processes. A36 plate thicker than 1-1/2" carries a slightly higher carbon limit of 0.29%, while plate from 3/4" to 1-1/2" stays at 0.25% max.

SMAW-LH를 사용한 A36의 이 예열 이유

Widely used structural carbon steel with 36 ksi yield and 0.26% max carbon. With low-hydrogen SMAW-LH, this combination falls under Category B rather than Category A, reflecting the lower hydrogen potential of the consumable. The 50°F minimum preheat is lower than what non-low-hydrogen SMAW would require at the same thickness. Low-hydrogen electrodes and inherently low-hydrogen wire processes reduce the driving force for hydrogen-induced cracking in the heat-affected zone.

A36의 일반적인 용도

Common in angle-to-gusset fillet welds, beam web clip angles, stiffener plates, base plate bearing connections, light bracing members, stair stringers, handrail posts, and miscellaneous steel fabrication. A36 plate is the default choice for connection elements such as shear tabs, moment end plates under 36 ksi demand, and simple beam-to-column seated connections. In retrofit and renovation, A36 angles and channels are standard for reinforcement brackets and framing infill. Typical shop drawing callouts include 3/8" and 1/2" A36 plate for gussets, 5/16" fillet welds on clip angles, and partial joint penetration groove welds on base plate stiffeners. A36 is so ubiquitous that most structural steel shops maintain permanent inventory in multiple thicknesses from 1/4" through 2" plate. Fillet weld sizes on A36 connections typically range from 3/16" minimum to 5/8" for heavy gusset-to-column welds, with E70XX electrodes providing significant overmatching strength.

3/4" to 1-1/2"에서 예열이 중요한 이유

Preheat climbs at this range as thicker material slows heat dissipation, trapping hydrogen at crack-susceptible grain boundaries.

3/4" to 1-1/2"에서 SMAW (low-hydrogen)를 사용하는 다른 강재

A36, SMAW (low-hydrogen)

다양한 조합 시도

인터랙티브 예열 계산기를 사용하여 D1.1:2025 표 5.11의 모든 강재, 공정, 두께 조합을 조회하세요.

A36 용접 가이드