One of my early mentors in my professional career would often reply to my application and performance-related questions with “it depends.”
While his reply frustrated me 25 years ago as young applications engineer, I’ve embraced the truth of it depends as I’ve matured. I wanted clear answers to help solve my customers process related questions, but I now understand that manufacturing environments are complex and standardized accelerated tests meant to help predict performance provide a mere starting point.
I was reminded of this recently as I prepared a quotation not to replace Izory® tube assemblies installed in a hydrochloric acid (HCl) bath over 11 years ago in 2011, but as part of a pending CAPEX project for new lines.
Our 7.3” x 37” Izory® tube assemblies had long ago surpassed the expectation of the prior tubes that needed replacement annually. As outlined in the corrosion resistance guidelines our material scientist Tyke Negas provided to me years ago (Table 1, which will be detailed later in this post), we recommend Izory®HD as a resilient material solution in HCl, but we would NOT have guaranteed it would survive for more than a decade guiding steel wire submerged in a 140°F bath of 24% HCl.
It is truly a reminder of how remarkable Izory®HD and its predecessor Izory® can perform in severe applications that require strength, and wear and corrosion resistance (Figure 1, below).
Figure 1. Izory® tube assembly holding steel wire in an acid bath for cleaning prior to coating with aluminum at Liberty Wire Johnstown.
General Guidelines for Predicting Corrosion Resistance of Izory®HD MgPSZ
1. Izory®HD MgPSZ is not resistant to aqueous fluids at temperatures are ≥200°C when exposed to significant loads due to the transformation of tetragonal phase to monoclinic zirconia. This phenomenon along with microcracking and crack deflection is what helps drive Izory’s fracture toughness, but it can also be a life limiting factor if the material is exposed to high temperatures and stress for extended time.
2. It is not resistant to H3PO4 (phosphoric acid) or HF (hydrofluoric acid) of fluids containing fluoride.
3. It is resistant to most common acids at < 100°C; acetic ((HC2H3O2), sulfuric (H2SO4), hydrochloric (HCL), etc.
4. Resistant to all organic-based solvents.
5. Not resistant to prolonged exposure to molten oxides or salts such a KOH, NaOH, K2CO3 and Na2CO3.
6. Resistant to high pH aqueous fluids at < 100°C.
Izory®HD , Refractron’s proprietary magnesia stabilized zirconia (MgPSZ) will reset your expectation for applications that require tough, strong, wear resistant, precise parts.
Izory®HD has helped our customers extend maintenance cycles, reduce costs, improve product quality and process reliability in many industries including those processing chemicals, producing oil and gas, and manufacturing wire. Contact us today to see if Izory®HD or our YTZP is right for you and to schedule a free engineering assessment.
Contributing Author: Adam Osekoski
Adam Osekoski is Director of Sales & Marketing at Refractron. Adam is a ceramic engineer with over 25 years experience designing, manufacturing and selling ceramics into critical applications like those drilling oil, drawing wire, metering chemicals and extending the life of high pressure valves. He can be contacted at +1 315 573 1134, adamo@refractron.com.