General Steel Knowledge | Clifton Steel

Steps For A Custom Fabrication Project

FreshySites — Thu, 10 Mar 2022 15:19:56 +0000

More often than not, projects in the steel industry are not one size fits all. In fact, it’s pretty rare when that happens. While Clifton Steel can provide simple products or steel plate, we specialize in customizing fabrication solutions, big and small. Here’s a look at what steps to expect when working with us �ǲ�ϵ��ȫƽ̨�� your custom fabrication needs.

Step one: discovery

First things first, we want to figure out what the customer needs. During an initial meeting, we’ll discuss the application where the customer may be experiencing material handling wear. There’s a chance they’re just in need of raw material �ǲ�ϵ��ȫƽ̨�� their own fabrication needs. Step one is all about discovering what problem the customer is having, and how we can help them solve it.

Step two: inspection and field measurement

Next up, field visit. During the field visit we thoroughly inspect the application and investigate the issue at hand. In most cases, we review an application showing wear that needs to be replaced. However, in some cases there is also a need �ǲ�ϵ��ȫƽ̨�� a design change. Typically, an initial and/or final field measurement is made from the existing equipment.

Step three: discussion and analysis

Now that we’ve seen what needs to be done, we chat with the customer about the best course of action to solve to the problem. We’ll make recommendations such as the best material to use �ǲ�ϵ��ȫƽ̨�� improved wear or any potential design changes to improve wear. If we’re looking at just replacement parts, we’ll cover the ease of replacement

Step four: engineering

If a new design is needed, our engineering team will develop it. When it’s complete, the sales representative will present the design to the customer �ǲ�ϵ��ȫƽ̨�� approval. For simpler applications, we develop a shop drawing �ǲ�ϵ��ȫƽ̨�� our use. When there are details that need to be confirmed, we’ll send to the customer �ǲ�ϵ��ȫƽ̨�� approval.

Step five: production

The liner or fabrication is produced in the shop utilizing ISO protocols and QC methods.

Step six: delivery

Time to send out the custom fabrication! We’ll work with the customer to coordinate a delivery plan.

Give us a call at 216.662.6111 or fill out our �ǲ�ϵ��ȫƽ̨��m to start a conversation about your custom fabrication needs.

The post Steps For A Custom Fabrication Project first appeared on Clifton Steel.

How To Extend The Life Of Your Hammers

FreshySites — Thu, 12 Aug 2021 14:12:31 +0000

In our industry, the biggest money waster is downtime. Nobody likes it, nobody wants it, but it exists and we have to deal with it. Just because we have to deal with it, however, doesn’t mean we can’t do everything in our power to minimize it.

Here are some common practices to extend the life of your hammers:

Avoid large volumes of hardened steel at one time. Hardened steel is tougher on the hammers, so the more you do at once, the more it breaks down your hammers. To extend the life, expand your hardened steel throughout the day.
Harden new hammers by running heavier material �ǲ�ϵ��ȫƽ̨�� a period of time. Prepping your hammers with this method will increase their strength and helps the integrity of the hammer last longer.
Install a new set of hammers in the center spots, harden them, then move them to the outside positions. Less material goes through the outside hammers than the center, so they don’t get hardened the way center positions do. Switch them out, then enjoy the benefits of hardened outside hammers.
Inspecting hammers at the end of the day and adding little welds to lower spots. This technique is more hands-on. When you notice a dip in a hammer, go ahead and weld a little extra in to bring that spot back up. This keeps your hammer more even and prolongs how much those spots will break down.
Invest in alloy hammers. They keep shape better by having harder key areas. It may cost more, but it will bring in a longer life �ǲ�ϵ��ȫƽ̨�� your hammers. Longer life means less time switching them out.
Work with manufacturers on the chemistry of your hammers. Hammers aren’t made the same, so what may work best �ǲ�ϵ��ȫƽ̨�� one company may not work best �ǲ�ϵ��ȫƽ̨�� another. Consider talking to your manufacturer to see if the chemical composition of your hammer is giving you the most bang �ǲ�ϵ��ȫƽ̨�� your buck.
Regular maintenance. Last but not least, take care of your hammers. With regular maintenance, you will see a longer life than if you just set them and �ǲ�ϵ��ȫƽ̨��get them.

We hope that those common practices help you extend the life of your hammers. Clifton Steel can help with all of your shredder needs! Learn more about what we offer here, and reach out to a Clifton Steel representative to talk about if we can save downtime with our products.

The post How To Extend The Life Of Your Hammers first appeared on Clifton Steel.

Grades Of Steel

FreshySites — Thu, 13 May 2021 11:34:56 +0000

What does “GRADE OF STEEL”mean?

Grades are used to differentiate between types of steel based on their chemical compositions and properties. There are standards set nationally and internationally so you can be sure you’re getting the same thing, no matter where you get it from.

How many grades of steel are there?

According to the World Steel Association, there are over 3,500 grades of steel. Wow, that’s a lot. No problem, we’ll talk about what to look �ǲ�ϵ��ȫƽ̨�� and how to narrow it down from 3,500 to a much more manageable number to choose from.

What goes into determining a grade of steel?

The amount of carbon the steel contains, if any, if the steel has any other alloying elements and how much, and the way the steel has been processed.

Where do I begin?

The amount of carbon the steel contains, if any, if the steel has any other alloying elements and how much, and the way the steel has been processed.

CARBON STEELS : – Roughly 90% of steel falls into this group. They only contain small amounts of elements other than carbon and iron. Subgroups- low/mild carbon steel (up to 0.3% carbon), Medium carbon steel (0.3-0.6% carbon), and High carbon steel (more than 0.6% carbon).

ALLOY STEELS – Added alloying elements into the steel such as nickel, copper, chromium, or molybdenum. Addition of alloys in different quantities influence properties such as strength, ductility, corrosion resistance, or machinability. Our post on 11 elements dives deeper into what each alloy does to steel.

STAINLESS STEELS – Everyone’s heard of stainless steel- it’s common in medical equipment, appliances, cutting tools, and piping. Stainless steel has a concentration of chromium ranging between 10-20%, which gives it a high corrosion resistance rating.

TOOL STEELS – This aids in hardening through heat treatment. It increases corrosion resistance and resistance to oxidation and high temperatures.

Contain tungsten, molybdenum, cobalt, and vanadium �ǲ�ϵ��ȫƽ̨�� increased heat resistance and a higher durability. It’s good �ǲ�ϵ��ȫƽ̨�� cutting and drilling equipment.

HOW DO I KNOW IT’S ALL THE SAME?

Governing Bodies �� Some of the well-known ones include (American Standard �ǲ�ϵ��ȫƽ̨�� Testing Materials), (American Society of Mechanical Engineers) (Society of Automotive Engineers) ANSI (American National Standards Institute), and (American Iron & Steel Institute). So, there are quite a few different options, but they all follow roughly the same outline. Their goals are also typically the same—to standardize steel production to be universally applied across many industries. These governing bodies give consumers of steel products confidence that the steel they are using will meet the requirements of their applications.

WHAT DO THE NUMBERS MEAN?

In carbon grades of steel, the numerical designation usually follows some sort of variation of 10XX, where the “XX�� describes the amount of carbon within that steel. For example, 1045 has a nominal carbon content of 0.45.
For grades of steel with particular physical property requirements, such as a tensile strength, yield strength, elongation, or hardness, there is a qualifier in the name. Each governing body uses something a little different, so we’re going to use ASTM as an example. ASTM uses a naming convention that typically begins with the letter “A�� (like A36, A572 Grade 50, or A514). In this case, A36 means the steel has a minimum of 36,000 PSI of yield strength.

HOW DO I KNOW IF I AM BUYING THE RIGHT GRADE FOR MY APPLICATION?

Steel has been produced since the mid 1800’s. Luckily, scientists and engineers have been able to improve and innovate the steel making process since those days. The governing bodies above have earned the respect and confidence of steel consumers through their countless hours of studying the chemistries of steel. When choosing the grade of steel �ǲ�ϵ��ȫƽ̨�� your application, it’s best practice to go with what was specified by the blueprint’s designer. If you don’t have those, or it hasn’t been established yet, talk to a Clifton Steel representative �ǲ�ϵ��ȫƽ̨�� help. Steel is our life, and we’ll be able to guide you in the right direction.

The post Grades Of Steel first appeared on Clifton Steel.

What Is Steel Plate?

FreshySites — Fri, 16 Apr 2021 13:34:15 +0000

What is steel plate?

Steel plate is a plate of metal, specifically steel, that can be cut and manufactured into a more elaborate product. Steel plates come in a range of thicknesses, and can be manufactured to a length or width that you need. There are common sizes that you’ll find, such as 48”x96�� or 96”x120��. To put it simply, steel plate is a general term.

Types of steel plate

As there are different sizes, there are different types of steel plate: stainless steel (commonly known), high-carbon, low-carbon, or alloy steel plates. Each of these types of steel plate are used �ǲ�ϵ��ȫƽ̨�� different applications, some may be household items while others are much larger, like buildings or tanks. For example, at Clifton, we sell AR400, AR450, and AR500 steel plates (amongst others). These are abrasion resistant carbon steel plates, which is the most prominent type of steel we have at Clifton.

How is steel plate made?

High temperature steel is rolled into sheets, where the steel gains strength. Multiple layers of steel are compressed together to create a single piece of steel plate, which can then be cut or burned to the specific size needed. The type of steel created is determined based on the composition of elements used in the molten metal. Check out our post on 11 elements of steel and what they do to learn more about what how different elements affect certain properties of steel.

Other �ǲ�ϵ��ȫƽ̨��ms of steel

Bars

Steel in the shape of a bar. Steel bars are commonly used in construction.

Looking �ǲ�ϵ��ȫƽ̨�� steel bars? We’ve got you, check out our page on steel bars to see what we have. Don’t see what you need? Contact us, there’s a good chance we can help out!

Click Here

Sheets

Sheets �� Thin, flat pieces of steel. Can be cut and bent into many shapes, super versatile. A lot of what we sell here.

Interested in steel sheets? We’ve got options. I’ll link to AR400, a popular product of ours. Explore our other products �ǲ�ϵ��ȫƽ̨�� more steel sheet options.

Click Here

Rolls

Steel that’s been run through rolls to be thinned out. Different types, hot rolled and cold rolled. Read more about those here.

Slabs

Considered a semi-finished product. Used mostly in the heavy machinery industry and �ǲ�ϵ��ȫƽ̨�� production of coils and plates.

The post What Is Steel Plate? first appeared on Clifton Steel.

Tensile Strength of Steel vs Yield Strength of Steel

FreshySites — Wed, 25 Nov 2020 11:16:55 +0000

What’s the Difference Between Yield Strength and Tensile Strength?

Knowing both the yield and tensile strength is important because they each have an impact on the production and use of steel (and many other materials, but we will focus on the steel). So, what’s the difference between yield strength and tensile strength? The biggest difference is that tensile strength is catastrophic, where yield strength is only a permanent de�ǲ�ϵ��ȫƽ̨��mation. Below we will go into more details about both of these, as well as talk about what elongation is in respect to tensile strength.

What Is Tensile Strength?

Tensile by definition means capable of being drawn out or stretched. Tensile strength is the resistance of steel to breaking under tensile tension. It’s used to specify the point when steel goes from elastic (temporary) to plastic (permanent) de�ǲ�ϵ��ȫƽ̨��mation. Usually, it’s measured in units of �ǲ�ϵ��ȫƽ̨��ce per cross-sectional area. Once a piece of steel is pulled past its tensile stress point, it will split apart.

Tensile strength of steel will show us how much tensile stress the steel can withstand until it leads to failure in two ways: ductile or brittle failure.

Ductile failure – think of this as the preliminary stage of failure, where it is pushed beyond the yield point to permanent de�ǲ�ϵ��ȫƽ̨��mation.

Brittle failure- this is the final stage where the tensile strength measurement is taken.

In essence, tensile strength is measured by the maximum stress that the steel can withstand while being stretched or pulled be�ǲ�ϵ��ȫƽ̨��e breaking.

What is Yield Strength?

Yield strength is the maximum stress that can be applied be�ǲ�ϵ��ȫƽ̨��e it begins to change shape permanently. This is an approximation of the elastic limit of the steel. If stress is added to the metal but does not reach the yield point, it will return to its original shape after the stress is removed. When the stresses exceed the yield point, the steel will not be able to bounce back. Yield strength represents the upper limit of the load that can be safely applied to the metal, which makes it a very important number to know when designing components.

Elongation

Elongation is the percentage of stretch from the original length of the steel to the point of failure, showing how ductile the steel is. Ductility is the capability of the steel to be stretched out without becoming more brittle or weaker in the process. The more ductile it is, the more �ǲ�ϵ��ȫƽ̨��mable the product is. Elongation is a good measurement to look at to determine if you’re choosing the right product �ǲ�ϵ��ȫƽ̨�� the project.

While tensile strength is important, you shouldn’t make your decision based solely on that. You also want to take into consideration the yield point, the difference between tensile and yield points, and the elongation percentage.

If you liked this post, check out our post on Hardness vs Hardenability to learn the differences between the two in the steel industry!

The post Tensile Strength of Steel vs Yield Strength of Steel first appeared on Clifton Steel.

Flatness In Steel

FreshySites — Tue, 31 Dec 2019 16:15:49 +0000

So, what exactly are we talking about when we mention flatness in steel? It’s simply the amount of space between the plate and a perfectly flat surface. One way it is measured is by placing the sheet on a flat surface and determining the distance from the surface to the highest point of the sheet, then subtracting the thickness of the material. Some people may just measure from the flat surface to the point where the steel starts. The most common specification �ǲ�ϵ��ȫƽ̨�� flatness is ASTM’s industry standards �ǲ�ϵ��ȫƽ̨�� flatness, which most companies follow. What happens if a piece of steel comes out and it’s not within the industry standard flatness tolerance? Well, there are a few different ways to flatten it out to get within tolerance. These include press breaking, roller leveling, and heat treatment. In this article, we’re going to look into each of these approaches, talk about realistic expectations to have when you receive your steel, and explain tolerance standards.

Flattening methods

Press Brake

A press brake is a machine tool that utilizes dies. The metal is placed between a matching set of dies to get the desired shape. The top portion is mobile while the bottom die is stationary. The press brake uses a V-shaped die to do this to give enough room to bend the steel. If it was a flat surface, the steel would just bounce back to the bend. The steel will be placed in the press brake where a bend or bow is, the top press is lowered just enough to bend the steel beyond the yield point. When it’s released, the bend will be flattened out.

Roller Leveling

Roller leveling is essentially a bending process. The steel goes through a series of alternating bends, which are created by going through upper and lower sets of leveling rollers. The rolls are able to be individually set �ǲ�ϵ��ȫƽ̨�� precision. The metal moves through like a wave, where the entry has the biggest wave and smallest is at the exit point. The steel comes out flat because of the alternating bends and decrease of bend intensity.

Heat Treatment

This is not recommended since the steel gets heated above the tempering point. The extreme heat changes the properties of the steel, which you want to avoid if you aren’t specifically trying to. After the steel is heated to a high degree, it needs to be cooled evenly through the quenching process. A cooling medium (water, polymer, or oil) will be used to create the desired grain structure of the steel by spraying the steel from the top and bottom. If the quenching portion is done evenly, the plate will be flat. If �ǲ�ϵ��ȫƽ̨�� some reason the quench is uneven, the plate may have a slight bend or wave to it. If the plate isn’t within tolerance, the heat treat process isn’t as precise as it could be. In that instance, it is best to use a secondary flattening technique. Many heat treat processes do not control the quench operation to provide a flat surface. In this case, they rely on a subsequent flattening method such as roller leveling or press braking to address the uneven control of quenching.

Realistic expectations

While I would love to be able to tell you to expect all of the steel you order to be perfectly flat, that wouldn’t be the case. It’s not a naturally flat material, but there are ways to flatten it out. Industry-wide standards exist, however that doesn’t mean they will match the tolerance that you require. Most of the time, people don’t take that into consideration to account �ǲ�ϵ��ȫƽ̨�� additional costs to reach their tolerances needed. It’s necessary to understand the manufacturing tolerances in order to determine if they meet your finished product tolerance, or if a flattening method is needed.

Another thing that tends to be overlooked is what happens to the flattened steel when it’s cut. Your pieces may not remain as flat as the plate. That is because when steel is flattened, stresses are caught inside the metal. When the metal is cut by saw, plasma, laser, waterjet, oxyfuel, or the steel is welded, those stresses are released. That can result in the cut pieces being less flat than the steel plate. Those pieces can sometimes be flattened to reach the tolerances needed.

Tolerances

Tolerances are different �ǲ�ϵ��ȫƽ̨�� every plate, depending on length, width, thickness, and type of steel. We talked about how ASTM created standards to follow, but companies are also able to set their own tolerances beyond that. For example, here at Clifton, we strive �ǲ�ϵ��ȫƽ̨�� ½ of the ASTM A6 standard. Although ASTM is the most widely used specification �ǲ�ϵ��ȫƽ̨�� flatness, some products have developed their own flatness specs, so a review of the spec you are using is advised.

Below is an example of part of the ASTM A6 commercial standards �ǲ�ϵ��ȫƽ̨�� heat treated plate. Contact us �ǲ�ϵ��ȫƽ̨�� further in�ǲ�ϵ��ȫƽ̨��mation on flatness tolerances.

Specified Thickness

Permissible variations from A Flat Surface �ǲ�ϵ��ȫƽ̨�� Specified Widths, In.

in inches	to 36, Excl.	36 to 48, Excl.	48 to 60, Excl.	60 to 72, Excl.
to 1/4, excl.	13/16	1-1/8	1-3/8	1-7/8
1/4 to 3.8, excl.	3/4	15/16	1-1/8	1-3/8
3/8 to 1/2, excl.	3/4	7/8	15/16	1-1/8

Flatness is a property of steel that is often not fully understood, and if not reviewed can make a huge difference in the profitability of your project. If you are unsure about flatness of a particular product or wish to discuss, please feel free to contact a specialist with us!

The post Flatness In Steel first appeared on Clifton Steel.

How is Steel Made?

FreshySites — Mon, 01 Apr 2019 04:07:28 +0000

Items we use every day come from steel- paperclips, tools, and cars to name a few. Sometimes you may wonder how those items are made, but have you ever wondered how the steel itself is made? Sir Henry Bessemer developed the first process �ǲ�ϵ��ȫƽ̨�� af�ǲ�ϵ��ȫƽ̨��dably manufacturing steel in 1856 called the Bessemer process. This process has become highly popular and has been adapted �ǲ�ϵ��ȫƽ̨�� mass production of steel. Different types of steel can be made, but it all starts with iron ore.

Iron ore is mined in many countries including Australia, Brazil, China, India, the United States, and more. Sedimentary rocks have iron deposits that are ground up to extract the iron ore by using a magnetic roller. Iron ore is mixed with coke (a fuel with few impurities and a high carbon content), usually made from coal. When these are heated together in a blast furnace molten iron, also known as pig iron, is �ǲ�ϵ��ȫƽ̨��med.

There are two different methods to make steel: basic oxygen and electric arc furnace.

Basic Oxygen Process (BOP)

To charge the furnace, we start with scrap steel. It’s used as a coolant to control high temperatures produced by exothermic reactions between the blast-furnace iron and oxygen. About 25% will be from scrap and 75% will be liquid iron. Oxygen is then blasted through a lance that is lowered into molten metal. The oxygen combines with impure elements, carbon, silicon, manganese, and phosphorus to produce an exothermic reaction. Lime is then added to the furnace to help separate other impurities and turn them into slag. This stage lasts about 20 minutes, then a sample is taken �ǲ�ϵ��ȫƽ̨�� the composition of the metal. Now we want to run the steel out of a tap hole into a ladle to separate the slag from the steel. If any adjustments in the chemical composition are needed, then a secondary steelmaking process begins.

Electric Arc Furnace (EAF)

The electric arc method uses high-current electric arcs to melt steel scrap and convert it to liquid. We begin by loading scrap steel into the EAF from overhead. The lid contains electrodes which are lowered into the furnace after it’s been put into place. The electric current is then passed through electrodes to �ǲ�ϵ��ȫƽ̨��m an arc. Once the heat is generated by the arc, the scrap will melt. Other metals are added to the scrap to give the steel the chemical composition needed during this process. Once everything is melted, oxygen is blown into the furnace to purify the steel. Lime and fluorspar are added to combine with impurities. Be�ǲ�ϵ��ȫƽ̨��e eliminating the slag, a sample is taken to check the chemical makeup. If the properties of the steel are good, the molten steel is poured into a ladle to be transported to the caster. This process typically takes about 90 minutes to make 150 tons.

Final Steps

Both processes end with the molten steel passing through casters and �ǲ�ϵ��ȫƽ̨��med into slabs, blooms, and billets. These �ǲ�ϵ��ȫƽ̨��ms are the primary steel products and can be trans�ǲ�ϵ��ȫƽ̨��med into a wide range of finished products that are then used to create the products you’re familiar with. Slabs are rolled into flat products, such as plates. Blooms are shaped into structural shapes, like beams, and billets are �ǲ�ϵ��ȫƽ̨��med into bars and rods.

The post How is Steel Made? first appeared on Clifton Steel.

Common Steel Industry Terms

FreshySites — Fri, 20 Jul 2018 11:23:29 +0000

We put together a short list of terms often used in the steel industry as a quick reference guide. While this does not give you the full meaning of the term, we hope it will provide some assistance while navigating our site and this industry!

AR – Abrasion Resistant. A type of steel that is tougher than mild steel and often used in high impact applications

Austenite – a metallic, non-magnetic bit of iron and carbon �ǲ�ϵ��ȫƽ̨��med when iron-based alloy is heated between 1382° F and 2642°F

BHN – Brinell Hardness Number. The number calculated through the Brinell Hardness test to determine hardness of steel

COC – Certificate of Con�ǲ�ϵ��ȫƽ̨��mance

Hardenability – the ability �ǲ�ϵ��ȫƽ̨�� material to be hardened by thermal treatment

Hardness – the resistance of steel to penetration

Overlay – a mild steel plate that is then fused or overlaid with chromium carbide

QMS – Quality Management System. A �ǲ�ϵ��ȫƽ̨��malized system that documents processes, procedures, and responsibilities �ǲ�ϵ��ȫƽ̨�� achieving quality policies and objectives.

Quench – rapidly cooling material

Temper – reheating and cooling material to improve hardness and elasticity

Tensile –the capability of being drawn out or stretched

TGP –Turned, ground, and polished (TGP) is a classification of finishing processes often used �ǲ�ϵ��ȫƽ̨�� metal shafting. Turning creates straight round bars without the strain induced by cold drawing, while grinding and polishing improves the surface finish and roundness �ǲ�ϵ��ȫƽ̨�� high dimensional accuracy

Tolerance –an allowable variation between the specified measurements and actual product

Yield –the maximum stress that can be applied be�ǲ�ϵ��ȫƽ̨��e permanent de�ǲ�ϵ��ȫƽ̨��mation

To learn more about a topic, check our knowledge center to see if we have a full post! If you still have further questions, feel free to reach out to us at 216.662.6111, we would love to help!

The post Common Steel Industry Terms first appeared on Clifton Steel.

What Is Hardness Vs. Hardenability

FreshySites — Sun, 06 May 2018 19:00:55 +0000

Two words commonly heard in the metal industry are hardness and hardenability. Derived from the same root, but a very different meaning. Hardness is a characteristic of the steel, while hardenability is describing an ability of the steel. In order to understand hardness, we first need to go through the process of determining this characteristic.

Testing For Hardness

Of course, there are tests to determine the hardness of the steel. Two of the most common ones are the Brinell and Rockwell tests. At Clifton, we utilize the Brinell, as this is considered the best practice �ǲ�ϵ��ȫƽ̨�� accurately determining hardness. Hardenability of material is tested by administering a high-pressure load (usually about 3,000 kgf) and a steel ball with a diameter of 10 mm as an indenter. The test load (which has been predetermined) is applied to the indenter, held �ǲ�ϵ��ȫƽ̨�� a specific period of time (also predetermined), then removed. The impression that has been left by the indenter is measured across at least two diameters, then averaged. At that point, a chart can be utilized to convert the averaged diameter to a Brinell Hardness Number (BHN). The larger the diameter, the softer the material is. We do this test on two opposite corners of our plates �ǲ�ϵ��ȫƽ̨�� consistency and accuracy.

The Rockwell test measures the depth of an indentation produced by a load on the indenter as well. With this method, however, there is a preliminary test �ǲ�ϵ��ȫƽ̨��ce that is applied to the metal, which breaks through the surface. The pretest �ǲ�ϵ��ȫƽ̨��ce is held �ǲ�ϵ��ȫƽ̨�� a specified time, then the depth of indentation is measured. After that is done, a major load is added to the preload. The �ǲ�ϵ��ȫƽ̨��ce is held again �ǲ�ϵ��ȫƽ̨�� a determined amount of time, allowing �ǲ�ϵ��ȫƽ̨�� elastic recovery. When the major load is released, the final depth of indentation is measured. The hardness value is derived from the difference in the baseline and final depth of measurement. That number is then converted to a hardness number. Just like with the Brinell test, the deeper the indent, the softer the material. Because the Rockwell test indenter is a diamond tip, the tested area is a finite point in the steel, which may provide a misleading hardness reading. The Brinell test covers a broader area and is more representative of the plate hardness.

Hardness

Now that we know how to determine hardness, let’s dive a little deeper. We know it’s a characteristic of the actual metal, but what does it mean? To put it simply, hardness is the resistance of the steel to penetration. There are different types of steel, �ǲ�ϵ��ȫƽ̨�� example, AR400 OR AR500, that are produced to a specific hardness. At Clifton, �ǲ�ϵ��ȫƽ̨�� steel to be considered AR400, the plate must measure between 360 and 440 BHN. AR500 steel plate measures between 477 and 550 BHN. You can find more in�ǲ�ϵ��ȫƽ̨��mation on other grades of steel on our products pages.

Hardenability

While hardness is a material property, hardenability describes the ability �ǲ�ϵ��ȫƽ̨�� material to be hardened by thermal treatment. To put this one simply, it talks about potential. When a piece of steel goes through thermal treatment, it’s called quenching and tempering. Tempering is heating the plate to a high temperature, and quenching is rapidly cooling the hot plate through a medium such as water, oil, or something else. When the steel is quenched, the outside of the plate is cooled rapidly. Depending on the thickness of the plate, the inner depths of the material may not cool as quickly. If it cools too slowly, the piece could have a softer core and a harder “shell��. Hardenability refers to the ability of the steel to be hardened by that process.

Testing

As with hardness, there is a test to figure out the hardenability called the Jominy test. This test was developed to provide a reference to determine the expected amount of decreased hardness from the surface to the center of the bar. This is better known as the H-band and is available on standard chemistries of alloy bars, which can be found online. To per�ǲ�ϵ��ȫƽ̨��m the test, a round metal bar of standard size is heat treated, then one end of the bar is quenched with room temperature water. The cooling rate will be highest at the quenched end and decrease with distance. After it’s cooled, a flat surface is ground along the test piece and a series of Rockwell hardness tests are taken in 1/16�� increments. While measuring, there will be a point that the quenched end of the material will begin to lose hardness and continue to decrease as you measure further.

Recap

To recap: hardness is how hard the actual steel is based on the resistance of penetration. Hardenability is the potential the steel has to be hardened by thermal treatment. Each of these has tests associated to come up with a measurement that is quantifiable. Hardness can be measured in any condition, at any time, with the Brinell or Rockwell test. Hardenability can be gauged by using the Jominy (H-band) tables that have been developed to show you the predictable hardness of a product from surface to core.

There are a number of factors that affect the hardenability of steel, the largest being chemistry. Certain elements added to steel, such as nickel or molybdenum, significantly increase the hardenability of steel. They’re normally added to alloy steels in large amounts in thicker plate or larger diameter bar. You can read more about elements in steel here. The heat treat process also has a dramatic effect on the hardenability of steel based on the media used to quench. Oil quenching is a slower quench than water, resulting in a softer steel.

In the end, hardenability and hardness are tools that allow you to determine whether a product can meet your needs �ǲ�ϵ��ȫƽ̨�� the fabrication process you are using. If you are �ǲ�ϵ��ȫƽ̨��ming, you will want to consider hardness and hardenability to determine if the product will �ǲ�ϵ��ȫƽ̨��m without cracking, and what radius and die openings are required. If you’re machining, you’ll want to know the hardness to be able to determine your timing. The harder the material, the more time it will take to machine the plates. If you are welding, you will have an area around the weld that will change in hardness as well.

If you need more assistance with determining suitability of a steel based on hardness and hardenability, please contact one of our product specialists at Clifton Steel.

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Anneal, Normalize, & Stress Relieve

FreshySites — Tue, 03 Apr 2018 10:51:41 +0000

In order to understand what annealing, normalizing and stress relieving is, we first need to understand what heat treatment is. The heat treat process is used to change physical or chemical properties of a material through austenitizing (heating material to a high temperature), quenching (quick cooling of material), and tempering (reheating plate at a relatively low temperature to improve properties). You can read more about this process in our previous post here. The Anneal, Normalize, and Stress Relieve processes are different than normal heat treat because there is no quenching or tempering process. Two key factors to these three processes are the temperature to heat the material to and the cooling time. The temperature used to heat the steel is based on the chemical composition of the product. In general, carbon is a key factor as well as alloying elements.

Anneal

In the annealing process there are three steps: heat, soak, and cool. To start, the steel is heated to the point of allowing recrystallization of the steel, which is considered the critical point (sometimes referred to the AC3 line). The steel is held at this temperature �ǲ�ϵ��ȫƽ̨�� a set amount of time be�ǲ�ϵ��ȫƽ̨��e slowly cooling in the oven. It’s important �ǲ�ϵ��ȫƽ̨�� it to cool very slowly to produce a refined microstructure. Annealing reduces the steel’s hardness and increases the ductility, making it easier to machine. The soaking time is generally considered as an hour per inch of thickness. Positive results: increased ductility, improved machinability, enhanced electrical conductivity

Normalize

The normalizing process is designed to relieve stresses, which results in improved ductility and toughness. The grain size is also enhanced and uni�ǲ�ϵ��ȫƽ̨��med in this process. Similar to the annealing process, the steel is heated to a temperature just beyond the critical point (again, the AC3 line) and held �ǲ�ϵ��ȫƽ̨�� a set period of time. This is when the smaller grains and high-energy grain shapes �ǲ�ϵ��ȫƽ̨��m. The steel is then cooled to room temperature; unlike annealing, we take the steel out of the oven �ǲ�ϵ��ȫƽ̨�� this part of the process. The soaking time is generally the same as it would �ǲ�ϵ��ȫƽ̨�� anneal.Positive results: relieved stress, enhanced grain size, improved ductility, improved consistency of microstructure

Normalization is one of the most common industrialization processes. This is partly because it’s less expensive than annealing. Since the steel doesn’t have to cool in the oven, the furnace is ready �ǲ�ϵ��ȫƽ̨�� the next plate as soon as the soaking stage is complete. In annealing, the plate must cool in the oven, which could take 8 to 20 hours. Normalization also produces harder and stronger heat treat plate.

Stress Relieve

Another heat treat process �ǲ�ϵ��ȫƽ̨�� steel is stress relieving. As the title suggests, it reduces the residual stresses that may have been caused by hot rolling, welding, or cutting. With this process, the steel is heated to a temperature below the critical temperature, resulting in little to no change to the material properties like there is with annealing and normalizing. This is typically used on lower carbon materials, such as A36.These are all processes that prepare steel �ǲ�ϵ��ȫƽ̨�� further processing. They allow �ǲ�ϵ��ȫƽ̨�� an easier time in machining, �ǲ�ϵ��ȫƽ̨��ming, and help minimize distortion while being worked. If you have further questions about the annealing, normalizing, or stress relieving processes and how they may be beneficial to what you’re looking �ǲ�ϵ��ȫƽ̨��, please contact a specialist with Clifton Steel.

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