Hey there! As a supplier of CK45 Carbon Steel Round Bars, I often get asked about the hardness of these bars. So, I thought I'd write this blog to share some insights on what the hardness of CK45 carbon steel round bar is all about.
First off, let's understand what CK45 carbon steel is. CK45 is a medium carbon steel that's widely used in various industries because of its good combination of strength, toughness, and machinability. It contains about 0.42 - 0.50% carbon, which gives it a decent amount of hardness compared to low - carbon steels.
The hardness of CK45 carbon steel round bar can vary depending on a few factors. One of the main factors is the heat treatment it undergoes. In its annealed state, CK45 steel has a relatively low hardness. Annealing is a heat - treatment process where the steel is heated to a specific temperature and then slowly cooled. This process relieves internal stresses and makes the steel more ductile. In the annealed condition, the hardness of CK45 carbon steel round bar is typically around 170 - 210 HB (Brinell hardness).
But if you want a harder CK45 round bar, you can go for quenching and tempering. Quenching involves heating the steel to a high temperature (usually around 820 - 870°C) and then rapidly cooling it in a quenching medium like oil or water. This rapid cooling forms a very hard and brittle structure called martensite. After quenching, the hardness of CK45 can shoot up to a very high level, sometimes even above 60 HRC (Rockwell hardness C scale).
However, martensite is extremely brittle, and that's where tempering comes in. Tempering is a secondary heat - treatment process where the quenched steel is heated to a lower temperature (usually between 150 - 650°C) and then cooled. This process reduces the brittleness of the martensite and improves the toughness of the steel. The hardness after tempering depends on the tempering temperature. For example, if you temper at a relatively low temperature (around 150 - 200°C), you'll get a high - hardness product, maybe around 55 - 60 HRC. But if you temper at a higher temperature (say, 500 - 650°C), the hardness will be lower, around 25 - 35 HRC, but the steel will be much tougher.
Another factor that can affect the hardness is the size of the round bar. Larger diameter bars may cool more slowly during quenching compared to smaller ones. This slower cooling can result in a lower hardness in the center of the bar, especially if the quenching medium is not able to penetrate effectively to the core. So, when you're specifying the hardness requirements for a CK45 carbon steel round bar, you also need to consider its size.
Now, let's talk about some of the applications of CK45 carbon steel round bars based on their hardness. For applications where high hardness and wear resistance are required, like in the manufacturing of gears, shafts, and piston rods, quenched and tempered CK45 bars are a great choice.
If you're interested in CK45 products with specific surface finishes and properties, we also offer CK45 Chrome Plated Round Bar. The chrome plating not only adds a layer of corrosion resistance but also enhances the surface hardness and smoothness. Our CK45 Hard Polished Hydraulic Piston Rod is another popular product. The hard - polishing process gives it a high - quality surface finish, which is crucial for smooth operation in hydraulic systems. And for those looking for a piston rod for hydraulic cylinders, our CK45 Hard Chromed Rod Hydraulic Cylinder Piston Rod is designed to withstand high pressures and wear.
In the automotive industry, CK45 carbon steel round bars are used in the production of various components. For example, engine parts like camshafts and crankshafts often require a good balance of hardness and toughness. Quenched and tempered CK45 bars can provide the necessary strength to withstand the high - stress conditions in an engine. In the machinery industry, they're used for making axles, spindles, and other rotating parts.
When it comes to machining CK45 carbon steel round bars, the hardness also plays a role. Softer annealed bars are easier to machine. You can use standard machining processes like turning, milling, and drilling without too much difficulty. But for hardened bars, you may need to use more advanced machining techniques and tools. For example, grinding may be required for finishing hardened CK45 bars to achieve the desired dimensional accuracy and surface finish.
If you're in the market for CK45 carbon steel round bars, it's important to work with a reliable supplier. As a supplier, we have the expertise to provide you with bars of the right hardness for your specific application. We can also offer advice on heat treatment and other processes to ensure that you get the best - performing product.
So, if you're interested in purchasing CK45 carbon steel round bars, don't hesitate to reach out. Whether you need a small quantity for a prototype or a large order for mass production, we're here to help. Just get in touch, and we can start discussing your requirements and how we can meet them.
References:
- ASM Handbook Volume 4: Heat Treating
- Metals Handbook Desk Edition, 3rd Edition
