FusoFlex

Cromomate-91:

Hydrogen controlled basic coated electrode.
Designed for welding 9Cr-1Mo steels modified with small additions of niobium, vanadium & nitrogen to derive better long term creep properties. Controlled addition of nickel is meant to impart better toughness after PWHT
Increasingly required in power generating plants, for headers, piping, turbine rotors.
Use of 9Cr-1 Mo modified steels is being progressively extended to other fields involving high temperature processes.

Identification:Name Printed

Carbon	Manganese	Silicon	Chromium	Molybdenum	Nickel	Vanadium	Columbium	Copper	Nitrogen	Sulphur	Phosphorus
0.08-0.12	0.6-1.20	0.30	8.0-10.0	0.90-1.20	0.8	0.15-0.30	0.04-0.08	0.15	0.03-0.07	0.01	0.010

Ultimate Tensile Strength kg/mm²	Yield Strength kg/mm²	Elongation (L=4d)%	CVN Impact Value Joules at +20°C
62	53	17	40

Ensure due control on hydrogen through adequate redrying for minimum one hour and preferably two hours.
As is known, hydrogen levels will drop as the redrying temperature is raised. Thus, 300°C for hydrogen 10ml/100 g, 350°C for hydrogen < 5ml/100 g and 400°C for hydrogen < 3ml/100 g.
Thereafter keep the electrodes in holding oven or quivers at 100°C.
Preheat & interpass temperature 150-250°C depending pon section thickness.
Upon Cooling to 100°C or lower is a good practice before PWHT.