A913 Gr.80のSAW (H4)用予熱 — up to 3/4"

SAW (H4) for A913 Gr.80 at up to 3/4"

H4-certified SAW (H4) for A913 Gr.80 at up to 3/4": minimum preheat 32°F (0°C) under Category G. H4 certification with SAW is the most difficult to achieve among all arc welding processes due to the large volume of granular flux involved. Flux moisture control must be exceptional — many SAW flux products cannot reliably achieve H4 levels even under ideal conditions. The limited availability of H4-certified SAW wire-flux combinations makes this designation uncommon in practice, which is one reason D1.1 Table 5.11 assigns SAW-compatible steels to categories that do not require H4.

SAW (Submerged Arc Welding)

SAW submerges the arc beneath granular flux for highest deposition rates, flat/horizontal only. Category B in Table 5.11.

SAW on high-strength plate requires careful selection of wire-flux combinations to meet both tensile matching and toughness requirements. F8A4-EA2 or similar high-performance combinations serve Category C steels. Heat input control is particularly important on TMCP grades because SAW naturally deposits high heat input due to the deeply penetrating arc.

SAW Tips for High-Strength and TMCP Steels

For A913 Grade 80 TMCP shapes (80 ksi yield, Category G, H4 required), SAW with H4-designated wire-flux combination is theoretically permitted but highly uncommon — very few SAW consumable combinations carry the H4 designator. Sourcing verified H4 SAW flux requires direct engagement with specialty consumable manufacturers. A higher-strength wire is also needed for tensile matching (EM12K at 70 ksi tensile.

Typical values for reference — always verify against your approved WPS and electrode manufacturer data.

Why SAW (H4) for A913 Gr.80 at up to 3/4"

Why SAW (H4) for A913 Gr.80 at up to 3/4"? SAW (H4) delivers 15-40 lb/hr deposition — the highest deposition rate among available processes. Position capability: flat and horizontal only. Suitability: shop only. The H4 designation provides the strictest hydrogen control available, which is mandatory for this steel grade under Table 5.11 — no other hydrogen level or standard low-hydrogen process is prequalified.

A913 Gr.80

ASTM A913 Grade 80 (80 ksi yield, 95 ksi minimum tensile) is the highest-strength TMCP shape specification in D1.1, produced exclusively by the QST process. It requires H4-certified consumables (the strictest hydrogen control at ≤4 mL/100g deposited weld metal per AWS A4.3) and falls exclusively under Category G, which has four thickness-dependent preheat tiers (32°F up to 3/4”, 50°F up to 1-1/2”, 150°F up to 2-1/2”, 225°F above). No other hydrogen designation, standard low-hydrogen, or non-low-hydrogen SMAW is prequalified for this grade under Table 5.11. The H4 requirement limits the available consumable pool significantly — only select electrode classifications carry the H4 designator. A913 Gr.80 availability is limited to heavy W14 column sections from a small number of domestic and international mills, with procurement lead times typically 16-24 weeks.

A913 Gr.80とSAWでこの予熱が必要な理由

Highest-strength 80 ksi TMCP shape requiring H4 consumables exclusively. This steel requires H4-certified consumables — the strictest hydrogen control in Table 5.11 at no more than 4 mL diffusible hydrogen per 100g. At 32°F with SAW, the four thickness-dependent preheat tiers in Category G reflect the balance between the steel's 80 ksi yield strength and the exceptional hydrogen control provided by H4 certification. No other hydrogen designation is prequalified for this grade.

A913 Gr.80の代表的な適用例

Reserved for the most demanding column applications in super-tall structures, typically interior gravity columns carrying 50+ stories of tributary load. A913 Gr.80 allows W14 sections to replace built-up box columns, simplifying connections and reducing fabrication cost while maintaining equivalent axial capacity. Every weld on this grade demands verified H4 consumables and documented preheat compliance — no exceptions or substitutions are permitted under Table 5.11. Column splice CJP welds require UT inspection per D1.1 Table 8.2. Only a limited number of domestic mills produce A913 Gr.80 shapes, with lead times of 16-24 weeks for non-stock sizes. The H4 consumable requirement eliminates most standard electrode inventory and requires dedicated electrode orders for each project. Fabricators must establish verified H4 supply chains before bidding Gr.80 column work, as H4-designated electrodes are not stocked by most welding distributors. Rejected consumable certifications can delay erection schedules by weeks.

up to 3/4"で予熱が重要な理由

Thin material sheds heat quickly, allowing hydrogen to escape the HAZ readily — lowest preheat tier in Table 5.11.

A913 Gr.80とSAW (H4)

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。

A913 Gr.80溶接ガイド