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Redi-Rail – Kromite CD60

IT IS A HUGE BENEFIT TO THOSE CUSTOMERS WHO PURCHASE ASSOCIATED STEEL KROMITE CD60 FINISHED RAIL TO BE ABLE TO JUST BOLT IT IN PLACE AND GET ON WITH THEIR LIFE. The manufacturer assumes the risk and accepts the liabilities associated with the production of the product.

ASSOCIATED STEEL;
“If we supply it, we stand by it”. We cannot guarantee the workmanship of our customer or their agents. Making finished hardened and machined custom wear rail is not for the faint of heart. Anyone who has done so knows there is truth in that statement.

Associated Steel has a Special Services Department (SSD) dedicated to custom fabrication. They have developed a specific fabricated rail from Kromite Cold Drawn Stock. Because of unique properties and characteristics, that product has been trade named; “Redi-Rail / Kromite CD60”.

Kromite CD60 is a semi-finished or finished rail that has been fabricated, to the customer’s specifications. Much like the unique processing technique used in the production of I.D. hardened wear pipe, the processing sequence and technique for Kromite CD60 is an inseparable component of the finished product. It is only CD60 when Associated Steel supplies it complete. Associated Steel has dedicated inventory, and devoted countless hours of engineering and refinement, toward making the highest quality product. CD60 is the product of an esoteric process. It has been field tested and proven to work exceptionally well. We do not share, nor do we release esoteric production technique or production sequencing information.

There is an “art” to making exceptional surface hardened rails, and that is why we trade-name finished and semi-finished rails. The actual process is an open-air process that is accomplished as much by sense and feel as by instructions and manuals. We have been supplying custom automation rails for over 50 years.

Occasionally, we will get a call from a customer who has made their own rails, advising they are getting low hardness readings. There are times where the actual hardness testing is the culprit. However, the majority of the calls could be avoided with a little bit of education. During the flame hardening process, De-carb is created on the surface of the bar. De-carb is that grey powdery coating that is visible on the surface that has been heat treated.
During the hardening process, carbon in the steel, at the surface, is burned off and disburses into the atmosphere. (No carbon, no hardness). Carbon near the surface can also burn off, although not completely. Testing into the De-carb will result in hardness readings that are not accurate, therefore a grind spot is recommended. A refined grain structure ensures the higher hardness range that we achieve after processing.

Surface hardening, when done correctly, allows the core of the bar to remain somewhat softer in order to maintain limited ductility. That is necessary for subsequent straightening and various other installation operations.

Heavier cross sections of flat bar retain more ductility. They are easier to work with during production and installation. Thinner flat bar will be more brittle and subsequently more difficult to manufacture and install. So, a 1” x 4” bar will generally be less troublesome than a piece of ¼” x 4”. On thinner sections, “crowning” across the flat becomes an issue and brittleness can come into play. At some point, if the ratio of thickness to width to length becomes unreasonable, Associated Steel will decline to quote. There are no charts to determine the exact point of concern. Experience and familiarity is required to make those determinations.

OUR COMMITMENT
To insure we provide the best possible hardened rails, we have developed unique jigs, fixtures, custom quenching mediums and procedures, at great expense to our company. There are times when we recognize that costlier additional processing procedures may be required. In rare instances, we may decline to quote certain configurations.

Associated Steel has the ability to provide custom surface hardened railroad type rails and custom hardened rail configurations specific to beef processing and other automation industries.

 

-Howard Thomas, August 6th, 2022

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Making Your Own Rails

Part 2 of 3

MAKING RAILS
a. if you start with cold rolled or cold drawn material remember that the manufacturing process for that product generally contributes to a noticeable amount of “retained stress”. That stress will tend to be released by temperature, and/or, vibration; meaning, while you are making the rail, or when the rail is in service.

b. if you start with a hot rolled bar, you must allow more stock removal, not only for potential decarb on the surface, but also distortion in shape (out-of-square, etc.). The mill allowance for out of square with hot rolled bars is significantly more than it is for cold drawn material. Often, a final grind is needed after processing.

So, there will be limits of what you can do to that piece of steel. Many variables will have to be taken into consideration. When we say, “Our steels machine better, weld better, or wear longer”, you must understand that is within a certain context. The statements we make are relative to other high strength steels used for maintenance applications (apples to apples). We are not saying they machine better than free-machining steel, or mild steel, or copper, or plastic.

A round bar that has been supplied as hardened from the mill, may not want to be straightened to a very tight T.I.R. To achieve a specific T.I.R. the straightener will have to overcome many factors. Consideration will have to be given to size vs length, the bar’s propensity to retain stress, etc. The operator will have to know something about the specific material’s “memory” properties and be familiar with all the potential conditions that might prohibit the required end result.

Conditions that might prohibit achieving that, are present in different forms for all fabrication jobs. They may relate to; number of pieces, grade, hardness, length, configuration, tolerance, surface finish, service temperature, etc. In addition, there are a limited number of companies offering value added services who are comfortable dealing with maintenance steels.

Metals fabrication shops only work with “serious” experienced companies, or the people they trust at those companies. They can easily lose faith in a job if you don’t have all the information needed. They can back away from a job if you keep feeding them additional or changing information every couple of days. Maintenance jobs cannot afford delays.

Metals fabrication is serious business. It is not a training ground for eager novices. Some words of wisdom you might want to tattoo somewhere on your person are: “Fabrication may be late, wrong, and dangerous.”, “Wear Plate is big and ugly!” and,” If you can’t stand the heat, stay out of that kitchen.”

Rule #1
Steels for maintenance and tooling need to be hard and tough. They need to resist abrasive wear, or gouging, or bending, or fatigue failure, or all of those issues.

Rule #2
Once you have made the base metal hard and tough, you have made a material that does not want to be messed with.

Let’s review
Making finished hardened and machined custom wear rail is not for the faint of heart. Anyone who has done so knows there is truth in that statement. If you are familiar with Murphy’s Law, when rail is being discussed, think of it as “Murphy’s Rail”.

 

-Howard Thomas, June 21st 2022

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