7018 H4r Rod

 

 

 

E7018-H4R is a low-hydrogen, all-position, high-strength welding rod. Its core advantages are low hydrogen crack resistance, all-position applicability, moisture resistance, and easy storage. It is one of the preferred welding rods for medium- and high-strength low-carbon steel/low-alloy steel structures (especially thick plates and high-constraint applications). It is widely used in steel structure welding (such as bridges, pressure vessels, and machinery manufacturing).

1. Low Hydrogen Properties, Excellent Crack Resistance
The low-hydrogen coating ("8") and H4-grade hydrogen content (≤4mL/100g) are its core advantages: the extremely low hydrogen content during welding effectively prevents "cold cracking" (cracks caused by hydrogen accumulation and restraint stress during the cooling process after welding). Therefore, it is often used in structures with extremely high safety requirements, such as pressure vessels and bridges.

2. Stable Weld Performance
The weld metal not only meets the required strength (≥483MPa) but also has good toughness (typically ≥27J impact energy at room temperature), meeting the strength and toughness requirements of most low-carbon steels (such as Q235 and Q345) and low-alloy steels.

3. All-Position Welding, Wide Applicability
The "1" position code allows welding in any position, eliminating the need to change welding rods due to structural constraints, improving construction efficiency.

4. Moisture-resistant design reduces pre-treatment costs.
The "R" design's moisture-resistant properties mean that unopened electrodes can be stored longer in a dry environment at room temperature (common low-hydrogen electrodes require tight sealing or refrigeration), reducing storage and drying costs. (However, if moisture is absorbed after opening, they must be dried at 350-400°C for 1-2 hours and stored in an insulated container at 80-100°C until ready for use. Otherwise, porosity may develop.)

1. Power Supply Requirements: DC reverse polarity (DCEN) must be used. AC power is prohibited (as this may cause arc breakage and porosity).

2. Drying and Storage:

• Unopened welding rods: Can be stored in a dry environment (humidity ≤ 60%) for 1 year.
• Opened welding rods or those that have absorbed moisture: Must be dried at 350°C for 1 hour (to remove moisture and prevent excessive hydrogen content). After drying, store in an 80-100°C insulated container and remove from use as needed. (If exposed to air for more than 4 hours after removal, re-dry the rod, and do not dry it more than 3 times, as this will cause the coating to fall off.)

3. Preheating and Postheating: When welding thick plates (≥25mm) or rigid structures, preheat to 80-150°C (adjust according to the carbon equivalent of the steel). If necessary, post-heat to 250-350°C after welding to accelerate hydrogen diffusion and further prevent cracking.

4. Welding environment: Avoid welding in an environment with humidity > 80% and wind speed > 8m/s (which can easily cause pores). Take wind and moisture-proof measures for outdoor welding.

Diameter × Length (mm × mm)	2.5×350	3.2×350	4.0×400	5.0×400
AC	80-120A	100-160A	140-210A	200-300A
DC ±	70-110A	90-160A	130-210A	180-300A

 

Payment Term:30% TT prepayment,70% TT before Delivery
Packing:5kg/Inner box,20Kg/Carton,1000kgs/Pallet
Production Time: Within 25days after receiving prepayment

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