Our alloy experts will be presenting their technical papers at AMPP Annual Conference + Expo in Denver, Colorado, March 20-23rd, 2023. Join our alloy experts as they present their technical papers during the conference.
Monday March 20, 2023
starting at 11:25am
Presenter: Javier Guerrero
Presentation Title: Corrosion Performance of Advanced Ni-Cr-Mo Alloys in Highly Concentrated Acids for Niche Chemical Processing Industry Applications.
Presentation Details: Two Ni-based corrosion resistant alloys, UNS N06035 and UNS N10362 alloys showed outstanding corrosion resistance compared to other Ni-based and high-grade stainless steel corrosion resistant alloys in uncommonly aggressive, niche conditions. Three cases are presented where each of these alloys exhibited excellent performance. The first case is UNS N06035 in the highly concentrated phosphoric acid “Wet Process” Production. For the second case, UNS N10362 plate heat exchangers for industrial-grade sulfuric acid (90 wt. % to 96 wt. % with many oxidizing impurities) production. The third case is again UNS N10362 which has also shown promising potentiodynamic polarization response in HCl concentrations higher than 20 wt. %. Previous electrochemistry reports of UNS N10362 have been limited to concentrations up to 20 wt. %. This works presents laboratory data and field tests that demonstrate the capabilities of UNS N06035 and UNS N10362 alloys to successfully operate in these uncommonly aggressive environments for the chemical processing industry.
Thursday March 23, 2023
starting at 8:10am
Presenter: Ling Chen
Presentation Title: Performance Of Corrosion-Resistant Alloys In Acidic Solutions Containing Bleach.
Presentation Details: Bleach has widespread applications in various industries, including pulp and paper, and water treatment. One of the key ingredients of bleach is sodium hypochlorite, which is a strong oxidant. Although sodium hypochlorite is extensively used in various industries, there is always a concern about failure of metallic components due to localized corrosion, especially in low pH-chloride solutions at elevated temperatures.
There are various alloying elements (including Nickel) that can catalyze pure sodium hypochlorite which limits the usage of a wide range of commercial alloys in bleach. However, in the chemical industry, process conditions seldom contain only sodium hypochlorite but rather a mixture of chemicals. Generally, titanium alloys are the preferred option in solutions containing bleach.
In the present study, several commercial alloys (Iron-base alloys, Nickel-base alloys, and Titanium-base alloys) were evaluated at elevated temperatures in low pH chloride solutions containing different concentrations of sodium hypochlorite. The results have shown no noticeable corrosion attack on base metal and welded regions of N06022, N06200 and R50400 alloy, whereas extensive corrosion attack on iron-base alloys (S31600, N08904 and N08367) occurred.
Thursday March 23, 2023
starting at 10:10am
Presenter: Bingtao Li
Presentation Title: High Temperature Nitridation Resistance of Several Modern High Temperature Ni- and Co-Based Alloys.
Presentation Details: High temperature nitridation is a common corrosion issue in the processes ranging from those containing air to those containing more specific gases, such as nitrogen or ammonia. High temperature alloys could provide good nitridation resistance, but the nitridation data of commercial alloys in nitrogen or ammonia at high temperatures, such as 871°C and above, is limited. The paper studies the high temperature nitridation resistant behaviors of six modern commercial high temperature Ni- and Co-based alloys, which include four chromia forming alloys, HAYNES® 230®, HAYNES® 188®, HAYNES® 625 and HAYNES® 617, and two alumina forming alloys, HAYNES® 214® and a recently developed HAYNES® 233™ alloy. The high temperature nitridation tests were conducted for 1,008h cycled weekly in ultra-high purity nitrogen gas at 871 and 982°C (1600 and 1800°F). The test results showed different nitridation resistant behaviors of the chromia and alumina forming alloys. Either chromia or alumina scales formed on these alloys to provide nitridation protection in the nitrogen atmosphere. HAYNES® 214® and 233™ alloys with the formation of an alumina scale exhibited excellent nitridation resistance at both temperatures, and pre-oxidation treatment to form an alumina scale was proven to be very effective to improve high temperature nitridation resistance. Chromia scale showed less protection, particularly at 982°C. The nitridation resistant behaviors of these alloys are analyzed and discussed.