How to Keep Nickel Bearing Alloys Free From Contamination

Posted by Tom McDevitt on May 3, 2016 7:00:00 AM

The effects of material contamination when dealing with nickel-bearing alloys used in high-temperature applications such as process furnaces is well documented.  Despite this awareness, and the subsequent impact on cost management and production schedules, there remains a constant stream of incidents where root-cause analysis identifies materials contamination as the problem.  Furnace rolls, mesh belts, muffles, refractory anchors, and more are some of the nickel-bearing items failing prematurely due to contamination.

One Industrial furnace customer believed they had adequate preventive measures in place to avoid incidents of alloy furnace parts contamination.  Their maintenance orientation program trained maintenance technicians in best practices when working on the company’s process furnaces; however that training omitted any reference to the importance of cleaning alloy furnace parts prior to installation.  The first-shift maintenance supervisor was aware of the need to decontaminate parts, but the newly hired, third-shift maintenance supervisor had no experience working with nickel-bearing materials, and the company’s lack of written procedures for furnace parts installation left the third-shift supervisor to his own ideas of how best to install an alloy-bearing wire-mesh furnace belt.

During one unscheduled maintenance outage, and at a time when production demands outstripped capacity, the company’s maintenance manager decided to change out a wire-mesh belt; a task left to the third-shift maintenance supervisor and his team.

The team member given the task of retrieving the new belt from inventory made what he believed was a good decision to transport the belt to the furnace line in a wheelbarrow.  To lighten the load and allow the belt to fit within the wheelbarrow, this team member removed the belt from its shipping crate, and removing the protective paper wrapping from around the belt, set the belt inside the wheelbarrow.  Unfortunately, the company’s machine shop used that wheelbarrow to transport machine turnings exposed in the machining process to sulfur-based cutting oils, and that sulfur-based oil transferred to the face of the mesh belt placed in contact with the bottom of the wheelbarrow.

With no written, standardized work process in place for installing furnace belts, and without the third-shift maintenance supervisor’s awareness of the importance to clean belts prior to installation, the worst-case scenario played out as the oil-contaminated belt went back into production.  One pass through the hot furnace was sufficient to drive the sulfur into the nickel-bearing alloy belt, and after that it was only a matter of time before the belt would fail.  When it did fail, maintenance reports indicated the belt looked a piece of wet paper.

There cannot be enough emphasis placed on proper handling and storage procedures for such alloy furnace parts.  As in this example, the costs for not having such work procedures is both real and disruptive when factoring in lost production capacity, especially at a time when the company was selling that capacity at a premium rate to support the needs of a valued customer.

The Rose Corporation’s Industrial Furnace division manufactures for customers world-wide all types and configurations of industrial furnaces such as batch type reheat and forging, tip-up, roller hearth, bell, car-bottom, vacuum, electric arc, and many more for both atmosphere and non-atmosphere, batch and continuous applications.  The Rose Corporation has manufactured industrial furnaces under both our RoseTM  and DreverTM  furnace brands, as well as manufacturing customized furnaces to our customer-supplied design.  We also manufacture dissociative, atmosphere generating equipment. 

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