A516 Gr.55/60 SMAW (non-low-hydrogen) 예열 — up to 3/4"

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 pressure vessel plate, non-low-hydrogen SMAW is typically limited to non-pressure attachments and temporary fit-up clips. Code requirements per ASME Section VIII often mandate low-hydrogen processes for pressure-retaining welds. Any E6010 tack welds on pressure boundaries must be completely removed before final low-hydrogen welding.

A516 Gr.55/60

ASTM A516 Grades 55 and 60 are carbon steel plates designed for moderate and lower temperature pressure vessel service. Grade 55 (55 ksi tensile, 30 ksi yield) and Grade 60 (60 ksi tensile, 32 ksi yield) are widely used in storage tanks, heat exchangers, and process drums. Chemistry limits (0.24% max carbon for Gr.55, 0.27% max carbon for Gr.60 on thicker plate) and typical carbon equivalent of 0.38-0.44 qualify them for both Category A (non-low-hydrogen) and Category B preheat in Table 5.11. A516 is produced in plate thicknesses from 1/4" through 12". Grades 55 and 60 may be ordered as-rolled, normalized, or stress-relieved depending on the ASME Code requirements for the specific vessel design temperature and thickness.

SMAW를 사용한 A516 Gr.55/60의 이 예열 이유

Pressure vessel plate for storage tanks and heat exchangers at moderate strength. At this thickness, SMAW with non-low-hydrogen electrodes places the joint in Category A of Table 5.11. The minimum preheat of 32°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.

A516 Gr.55/60의 일반적인 용도

Specified for atmospheric storage tank shells per API 650, heat exchanger tube sheets, air receiver vessels, condensate drums, deaerator shells, and low-pressure separator vessels. A516 Gr.60 is the workhorse for ASME VIII Division 1 vessels under 650°F design temperature. Shell-to-head circumferential seams and nozzle reinforcement pads are the primary weld details. Plate thicknesses for API 650 tank shells typically range from 5/16" at the top course to 1" or more at the bottom course depending on tank diameter and liquid specific gravity. Vertical seam welds carry the full hydrostatic head and require complete joint penetration with radiographic examination. Tank diameters range from 15 feet for small day tanks to over 300 feet for crude oil terminal storage. Shop-welded vessel shells are rolled from flat plate with longitudinal seams welded first, then circumferential seams joining shell courses together on the vessel rotator.

up to 3/4"에서 예열이 중요한 이유

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

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

A516 Gr.55/60, SMAW (non-low-hydrogen)

다양한 조합 시도

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

A516 Gr.55/60 용접 가이드