A36のSMAW (non-low-hydrogen)用予熱 — 3/4" to 1-1/2"

SMAW (Non-Low-Hydrogen)

Non-low-hydrogen SMAW (E6010/E6011) uses cellulosic electrodes with higher hydrogen potential, assigned to Category A in Table 5.11.

For common structural shapes and plate, non-low-hydrogen SMAW with E6010 or E6011 excels at root passes on open-root groove welds where burn-through control matters. Vertical-up technique with a slight weave keeps the puddle manageable. Rod consumption runs about 10-12 electrodes per pound of weld metal deposited. Electrode stubs should be no shorter than 2 inches to maintain adequate arc length control.

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.

A36とSMAWでこの予熱が必要な理由

Widely used structural carbon steel with 36 ksi yield and 0.26% max carbon. At this thickness, SMAW with non-low-hydrogen electrodes places the joint in Category A of Table 5.11. The minimum preheat of 150°F compensates for the higher diffusible hydrogen from cellulosic electrode coatings. The thicker the material, the longer hydrogen takes to escape the heat-affected zone, which is why preheat rises with thickness even for this common grade.

A36の代表的な適用例

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"で予熱が重要な理由

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

SMAW (non-low-hydrogen)と3/4" to 1-1/2"における他の鋼材

A36とSMAW (non-low-hydrogen)

別の組み合わせを試す

インタラクティブ予熱計算機を使用して、D1.1:2025 表5.11のあらゆる鋼材・プロセス・板厚の組み合わせを検索できます。

A36溶接ガイド