التسخين المسبق لـ A633 Gr.E مع SMAW (low-hydrogen) — 3/4" to 1-1/2"
الحد الأدنى لدرجة حرارة التسخين المسبق وبين الممرات لـ A633 Gr.E الملحوم بـ SMAW (low-hydrogen) عند سماكة 3/4" to 1-1/2"، وفقاً لـ AWS D1.1:2025 الجدول 5.11.
مبني على AWS D1.1:2025 الجدول 5.11 — كل قيمة متتبعة إلى البند.
عملية SMAW أو SAW أو GMAW أو FCAW منخفضة الهيدروجين (فولاذ عالي المقاومة)
SMAW (Low-Hydrogen)
Low-hydrogen SMAW (E7018/E7016) uses basic-coated electrodes requiring rod oven storage, assigned to Category B in Table 5.11.
On pressure vessel plate, E7018 is the standard manual electrode for nozzle welds, manhole reinforcements, and repair welding. ASME Section IX procedure qualifications typically require all-weld-metal tensile and guided bend tests. Rod moisture control is critical in vessel fabrication because vessel codes impose stricter hydrogen limits than structural codes.
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.
لماذا هذا التسخين المسبق لـ A633 Gr.E مع SMAW-LH
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 150°F minimum with SMAW-LH, the preheat ensures the cooling rate stays slow enough to prevent hydrogen-induced cracking in this higher-hardenability material. Category C steels demand careful attention to interpass temperature control throughout the weld sequence.
التطبيقات النموذجية لـ A633 Gr.E
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.
لماذا يهم التسخين المسبق عند 3/4" to 1-1/2"
Preheat climbs at this range as thicker material slows heat dissipation, trapping hydrogen at crack-susceptible grain boundaries.
التسخين المسبق الفئة C لـ A633 Gr.E
الفئة C في الجدول 5.11 تنطبق على الفولاذ عالي المقاومة حيث يتطلب مزيج قابلية التصلب والإجهاد المتبقي تسخيناً مسبقاً مرتفعاً. لـ A633 Gr.E عند 3/4" to 1-1/2"، التسخين المسبق الأدنى 150°F يبطئ معدل تبريد اللحام لمنع تشكل المارتنسيت القابل للتشقق في المنطقة المتأثرة بالحرارة.
أنواع فولاذ أخرى مع SMAW (low-hydrogen) عند 3/4" to 1-1/2"
| الفولاذ | الفئة | التسخين المسبق |
|---|---|---|
| A36 | B | 50°F (10°C) |
| A53 Gr.B | B | 50°F (10°C) |
| A106 Gr.B | B | 50°F (10°C) |
| A709 HPS70W | C | 150°F (65°C) |
A633 Gr.E مع SMAW (low-hydrogen)
جرّب تركيبات مختلفة
استخدم حاسبة التسخين المسبق التفاعلية للبحث عن أي تركيبة من الفولاذ والعملية والسماكة من D1.1:2025 الجدول 5.11.
أدلة لحام A633 Gr.E
بيانات مرجعية D1.1:2025. غير تابع لـ AWS.