AWS D1.1:2025 · 表5.11 · カテゴリーC

A633 Gr.EのSAW用予熱 — over 2-1/2"

A633 Gr.EをSAWで板厚over 2-1/2"で溶接する場合の最低予熱およびパス間温度。AWS D1.1:2025 表5.11に基づく。

AWS D1.1:2025 表5.11に基づく — すべての値は条項に追跡可能。

最低予熱・パス間温度
300°F / 150°C
カテゴリーC
低水素SMAW、SAW、GMAW、またはFCAWプロセス(高強度鋼)
AWS D1.1:2025 表5.11、§5.7
参考ツール。プロジェクト適用版およびエンジニア承認済みWPSで確認すること。

SAW (Submerged Arc Welding)

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

For pressure vessel longitudinal and circumferential seams, SAW is the primary process. Tandem or multi-wire configurations on specialized manipulators achieve consistent quality over seam lengths exceeding 40 feet. Flux basicity index per ASME Section II Part C determines the mechanical properties of the weld deposit.

SAW Tips for Pressure Vessel and Low-Temperature Steels

For A633 Grade E (60 ksi yield, Category C, Q&T/NT), SAW requires a higher-strength wire-flux combination — F8A4-EA2 or F8A6-EM12K provides 80 ksi weld metal tensile matching. Category C preheat minimum: 50°F up to 3/4", 150°F up to 1-1/2", 225°F up to 2-1/2", 300°F above. The normalized-and-tempered condition means HAZ properties are sensitive to SAW heat input — limit to 40–55 kJ/in on thick sections.

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

Filler Metal for SAW

Wire: EM12K or EL12 with matching flux (AWS A5.17). Common combo: F7A2-EM12K. Diameter: 3/32" or 7/64". Flux type: active (A) for single-pass, neutral (N) for multi-pass. Voltage: 28-34V. Current: 400-800A depending on joint size. Travel: 12-24 ipm.

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

A633 Gr.E

ASTM A633 Grade E is the highest-strength grade in this specification with 60 ksi minimum yield and 80 ksi minimum tensile strength (for plates up to 4”). Produced as normalized and tempered plate, it provides exceptional notch toughness with CVN testing at -60°F (15 ft-lbs transverse). Its higher strength level places it in Category C of Table 5.11, with correspondingly higher preheat requirements than the A/C/D grades. The quenched-and-tempered condition means carbon content is higher (0.22% max) with controlled manganese (1.15-1.50%) and silicon (0.15-0.50%), producing a CE-IIW of approximately 0.44-0.50. Like all Q&T steels, maximum interpass temperature must be respected to avoid degrading the tempered microstructure in the heat-affected zone during multi-pass welding.

A633 Gr.EとSAWでこの予熱が必要な理由

Highest-strength A633 grade at 60 ksi yield requiring Category C preheat. The higher strength level of this steel places it in Category C of Table 5.11, which carries elevated preheat requirements compared to Category B grades. At 300°F minimum with SAW, the submerged arc process with granular flux produces controlled hydrogen levels, with flux condition being the primary variable, but the preheat must still ensure the cooling rate stays slow enough to prevent hydrogen-induced cracking in this higher-hardenability material.

A633 Gr.Eの代表的な適用例

Found in heavy-duty crane runway girders for steel mills, offshore jacket legs, polar Class vessels, cold-region bridge main members, large-span roof trusses in Arctic facilities, and load-bearing elements in LNG terminal structures. A633 Gr.E combines 60 ksi yield with excellent low-temperature toughness (CVN testing at -60°F), making it suitable for primary structural members in environments where both high static loads and extreme cold coincide. Procurement lead times for A633 Gr.E plate can be 12-16 weeks due to limited domestic production, and plate availability above 2" thickness may require international sourcing. Repair welding requires the same preheat procedures as original fabrication to maintain the guaranteed toughness properties. Filler metal selection must provide tensile matching (80 ksi minimum) and cold-temperature CVN values that equal or exceed the base metal specification. Weld mockups for offshore and LNG applications typically undergo CTOD or wide-plate testing.

over 2-1/2"で予熱が重要な理由

The heaviest sections demand the highest preheat in Table 5.11. Multi-pass sequences require maintaining interpass temperature throughout.

A633 Gr.EのカテゴリーC予熱

表5.11のカテゴリーCは、焼入性と残留応力の組み合わせにより高い予熱が必要な高強度鋼に適用されます。over 2-1/2"のA633 Gr.Eにおいて、300°Fの最低予熱は溶接冷却速度を遅くし、熱影響部での割れ感受性マルテンサイトの生成を防ぎます。拘束された継手の多パス溶接では、パス間温度をこの最低値以上に維持することが特に重要です。

SAWとover 2-1/2"における他の鋼材

鋼材カテゴリー予熱
A36B225°F (110°C)
A53 Gr.BB225°F (110°C)
A106 Gr.BB225°F (110°C)
A709 HPS70WC300°F (150°C)

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。

over 2-1/2"でSAWを使用したA633 Gr.Eの最小予熱温度は?
A633 Gr.EをSAWでover 2-1/2"の板厚で溶接する場合、最低予熱温度はAWS D1.1:2025 表5.11、カテゴリーCに基づき300°F(150°C)です。これはパス間温度の最低値でもあり、パス間でも継手が300°F以下に冷却されてはなりません。
A633 Gr.EとSAWに適用される表5.11のカテゴリーは?
SAWで溶接されたA633 Gr.Eは、AWS D1.1:2025 表5.11のカテゴリーCに該当します。低水素SMAW、SAW、GMAW、またはFCAWプロセス(高強度鋼)。over 2-1/2"板厚では、このカテゴリーは最低予熱300°F(150°C)を要求します。
over 2-1/2"でのA633 Gr.Eの予熱が300°Fである理由は?
SAWでのover 2-1/2"板厚におけるA633 Gr.Eの300°F予熱は、鋼材の焼入性とこの板厚での拘束の増大の組み合わせを反映しています。高い予熱は熱影響部の冷却速度を遅くし、鋼材が割れ感受性ミクロ組織に変態する前に拡散性水素が逸散する時間を与えます。

D1.1:2025参考データ。AWSとの提携なし。