How To Heat Treat RWL 34 In A Gas Forge

Heat Treating RWL 34 In A Gas Forge:

RWL 34 can be heat treated in a gas forge by using a thermocouple as temperature control.

History:

Swedish makers Damasteel are famous for their stainless steel damascus in amazing patterns. Central to their Damasteel products is the RWL 34 steel, by many considered to be one of the best knife steels on the market. This is due to high edge retention and sharpness, as well as ease of machining and polishing. RWL is named after R W Loveless (Bob Loveless) one of the most innovative knife makers of the last century. 

Forging: 1050-1160 °C  (not recommended)

RWL 34 can be forged in small sections, hot working temperatures 1050-1160 °C ( 1920 - 2120 F). Forging by hand in larger dimensions is difficult due to the almost double deformation resistance to simple carbon steels. Slow cooling after forging is recommended due to increased risk of cracking while cooling. No grinding is recommended without annealing, due to high risk of cracking.

Annealing: 900°C for 1 hour, cool to 750°C over 1 hour, then hold at 750°C for 4 hours. (1650F - 1380F - 1380F) Annealing is here considered out of scope for amateur knife makers with a gas forge (furnace) due to long hold times.

Heat treating (Hardening)*:

• Hold at 1080°C for 8 mins for a 3.2 mm thick blade. Add or remove 30 sec per 0.5 mm difference in thickness.
• Quench in oil. Plate quenching also works, you have 2 mins to get the steel to room temperature.
• Place in deep freezer for 1.5 hours (-18°C / -0.4 F)
• Temper once for 2 hours at 225°C (345 F) for 58-59 HRC

*Damasteel suggests several combinations of temperature for hold, deep freeze and tempering, this is one of these.

Quench temperature can be either 1050 °C or 1080°C, note tempering temperature is listed as either 175°C or 225°C. The figure above shows 175°C while the profile below lists 225°C.

Chemical composition for RWL 34:

This was our summary from the Damasteel instructions retrieved the 23/05/2018 from on http://www.damasteel.se/files/2614/1104/3058/Product_Information_RWL_34.pdf