Recommendations for Welding

Good welding practices such as full die/mold preheating and stress relieving after welding (full process weld) makes all the difference in weld quality and preventing pin hole porosity and cracking during welding whether it’s before or after DYNA-BLUE/DYNA-BRITE.  Engineering changes and repairs can be accomplished on DYNA-BLUE/DYNA-BRITE treated surfaces by machining if needed with carbide cutters and welding per welding instructions below. 

1. Die Preparation

We recommend that the die/mold be cleaned of all residuals (plastics, aluminum, etc) and oxides before welding. A successful method is:

• Blast with Glass Bead or mixture of 220 Aluminum Oxide with 100% coverage at low pressure to maintain micro finish.
• Bevel cut the area to be filled 90 degrees.

2. Welding Procedure

• Preheat the die to minimum of 950°F. Use weld rod identical to the base material, such as H-13, P-20, etc.
• Use proper rod and gap angle (rod angle 10-15°, arc gap angle equal to diameter of weld rod.) 
• For MIG welding use appropriate wire material (see #1 above) and the heaviest inert gas possible. For multiple pass welding start at the root of the bevel and make multiple passes, from left to right then the middle until the bevel is slightly overfilled. 

3. Machine welded area

• Machine /bench welded area to desired finish. If porosity is present there is a high probability that the shielding gas was disrupted. Die penetrant, magnetic particle inspection or acid etching can be used to verify integrity of the weld.

4. Stress Relieve

Stress relieve/temper at a temperature of 50°F less than the original tempering temperature or at a minimum of 1000°F for DYNA-BLUE 6B or 8B, and 1050°F for DYNA-BLUE 5D or 8D. Hold for 1 hour per inch of thickness. This will temper the weld material and also relieve welding stresses.