Flame Hardening In-House; Two Major Considerations

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This week, let’s talk shop – what to consider when deciding to do flame hardening on your shop floor. In design, there are two major considerations: engineering and budget estimate. When customers come to us wanting to design and implement an in-house flame hardening solution, we work with them to first establish a reasonably accurate engineering scope of the project so they can determine whether their budget figures are realistic. The quality of the work put into a project in this “discovery” phase determines the quality of the final implementation and production work. We at FTSI take it very seriously.

The most important predictor of the solution’s design is the parts being hardened themselves. How big are they — will they be handled and positioned by a crane or a robot or a person? Where is the area that needs to be hardened, i.e., what are the heat treat specs for each? How many need to be hardened per shift? Will flame hardening be integrated into the entire line or be put into its own room or space? We like to get an idea of how the customer is thinking of the implementation during this initial “discovery” phase.

These initial considerations impact the size, and therefore the cost, of the total flame hardening solution – not just the footprint of the machine, but the quantity of fuel and oxygen required, whether a heat removal hood is needed, or what kind of quench solution is needed. Remember, it’s not just the heat, it’s the cool. Will the quench need a chiller to keep the right temperature under a high production rate? How much quench will get the hardness required, and what is the best type and amount of polymer to add to it?

The answers to these questions determine the project scope: from there, you can get equipment costs, production costs, and footprint and physical requirements in the plant. (link to Blog Post #9) People don’t usually understand why this information matters so much, but it is absolutely critical to getting the most cost-effective and highest quality solution.

Once we’ve finished the discovery phase, we like to move into a “concept testing” phase where we can design on a small scale a solution to prove that the hardening concept will work.

One of the biggest keys to successful flame hardening lies with flame head design and configuration. To meet the heat treat specifications, you may need four flame heads, or two, or one with progressive design. These design decisions also help to determine your production costs – how much fuel, oxygen, water, electricity, and cycle time the machine will require once on the shop floor. Nobody likes surprises in project management, particularly when they drive up budget estimates. Our “concept testing” phase helps us unearth the surprises before they have a big impact on the project.

To begin this phase, we ask customers to supply us with spare parts. Then we design the flame heads, cycle and quench, harden the parts ourselves, do the destructive testing and get the hardness level and pattern that is required by the spec. We want to be sure that the design and process work as expected before we ask the customer to spring for the cost of an entire solution.

For the minimal cost of tooling, setup, and testing, which total a fraction of the cost of a full custom solution, we can test and prove out the specs before actual project work starts. About 2/3 to ½ of the cost for “concept testing” is credited to the cost of the entire solution. We find that the concept testing phase delivers the most realistic scope for any project, increases engineering and testing efficiencies of the project (therefore reducing overall costs), and results in a faster, more satisfactory experience at the customer site during implementation time.

Other costs you need to factor into a budget for a full in-house flame hardening solution include maintenance and spare parts. You will need to regularly clean, and eventually replace, flame heads.

I hope this has been a helpful overview of design considerations for budgeting and engineering your in-house flame hardening solution. It isn’t rocket science, but it does require knowledge of those design decisions that can have far-reaching consequences. The only surprise we like to see at the implementation is a pleasant one at how well the experience surpassed expectations. As always, if you have any questions about designing your heat treating solution, email me at mark@flametreatingsystems.com or call 919-956-5208.


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