Today’s pulp mills can be considered as bio-refineries. The different parts of the process pose very different demands on the materials used. Some of the process steps require chip cutters, digesters, conversion boilers bleach lines and finally paper machines. For wood chipping, Creusabro is a series of steels with high wear resistance with properties well suited for this application. For digesters, operating at high temperatures and pressures, it is important to have a good corrosion resistance in caustic medium in combination with high strength. This makes duplex stainless steels the materials of choice for this application. Pulp bleaching is a process that has undergone major changes over the past two decades in an effort to reduce pollution by chlorine. The predominant technique is now elemental chlorine-free bleaching. Duplexes , high-end superaustenitics and sometimes even titanium alloys are used for this end of the installation. Other applications in the pulp factory include conversion boilers, storage tanks for white, green and black liquors, all with their specific requirements on steel grade to withstand corrosion. For paper machine parts, preferred materials in the past have been 304L and 316L stainless steels, sometimes with enhanced machinability provided by the Fastinox treatment. Viable alternatives with high mechanical strength and comparable corrosion resistance are UR 2202 and UR 2304

• Industeel

• Alloy Steel

• Digester

• Corrosion

• Product Description