A913 Gr.50/60/65のSAW用予熱 — over 2-1/2"

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 Grades 50/60/65 TMCP shapes (CE-IIW 0.35–0.42), SAW is limited to flat-position shop fabrication of built-up sections — most A913 work involves W-shape splices welded in positions impractical for SAW. Where flat-position SAW is feasible, use 3/32" EM12K at 400–550 A with neutral flux. D1.1 Clause 7.7 heat input limitations do NOT apply to A913/A913M — SAW high heat.

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

Why SAW for A913 Gr.50/60/65 at over 2-1/2"

Why SAW for A913 Gr.50/60/65 at over 2-1/2"? SAW delivers 15-40 lb/hr deposition — the highest deposition rate among available processes. Position capability: flat and horizontal only. Suitability: shop only.

A913 Gr.50/60/65

ASTM A913 Grades 50 (50 ksi yield), 60 (60 ksi yield), and 65 (65 ksi yield) are quenched-and-self-tempered (QST) structural shapes produced by thermo-mechanical controlled processing (TMCP) — an in-line water quench immediately after the final rolling pass, followed by self-tempering from the core heat. This produces a fine-grained bainitic/ferritic microstructure throughout the full cross-section with carbon content typically 0.10-0.16% and CE-IIW of 0.35-0.42. Standard low-hydrogen processes use Category B; H8-certified consumables qualify for the reduced Category D (32°F all thicknesses), reflecting the inherent hydrogen cracking resistance of the TMCP microstructure. Available exclusively as W-shapes (primarily W14 heavy column sections), A913 is not produced as plate or other forms. The QST process eliminates the need for separate mill heat treatment, providing consistent through-thickness properties.

A913 Gr.50/60/65とSAWでこの予熱が必要な理由

TMCP structural shapes for seismic frames with H8-eligible reduced preheat. This steel is prequalified only with low-hydrogen processes under Table 5.11. With SAW, the submerged arc process with granular flux produces controlled hydrogen levels, with flux condition being the primary variable. The 225°F minimum preheat balances the steel’s strength level and carbon equivalent against the hydrogen control provided by SAW. Non-low-hydrogen SMAW is not an option for this grade under D1.1 prequalified WPS.

A913 Gr.50/60/65の代表的な適用例

Specified for seismic moment frame columns, high-rise building corner columns, transfer girder bearing seats, heavy truss chords, stadium cantilever support columns, and parking garage moment frame members. A913 TMCP shapes eliminate the need for post-rolling heat treatment, providing consistent through-thickness properties from flange tip to web center. Column splice CJP welds and beam-to-column continuity plate fillet welds are the critical weld joints. Available in W14 sections from W14x132 through W14x730, these shapes are the backbone of seismic column design in high-rise construction. The TMCP process creates a fine-grained microstructure throughout the full cross-section, unlike conventional heat-treated shapes that may have property gradients. The H8 path to Category D (32°F all thicknesses) offers significant fabrication cost savings on heavy column splices that would otherwise require 150-225°F preheat under Category B. Column flange thicknesses on W14x455 and heavier sections exceed 3".

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.

SAWとover 2-1/2"における他の鋼材

A913 Gr.50/60/65とSAW

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.50/60/65溶接ガイド