The elements added to free-cutting steel include S, Pb, Ca and P. Their main functions are as follows:
1. The role of sulfur
Sulfur forms MnS inclusions with Mn in steel, which can interrupt the continuity of the matrix, make the chips easy to break, and reduce the contact area between the chips and the tool. Sulfur can also reduce friction and prevent the chips from adhering to the cutting edge. However, the presence of sulfur can make steel hot and brittle, so the sulfur content is generally limited to the range of w(s)=0.10%~0.30%, and the Mn content should be appropriately increased to match it.
2. The role of lead
The addition of Pb can improve the cutting performance of steel. Since Pb does not dissolve into ferrite in steel and does not form compounds, it is in a free state and forms fine particles (2~3μm) uniformly distributed in the matrix structure. When the heat generated during the cutting process reaches the melting point of the Pb particles, it is in a molten state and becomes a "lubricant" between the tool and the chips and between the tool and the workpiece surface, reducing the friction factor, the tool temperature, and the wear. The amount of Pb added is in the range of w(Pb)=0.1%~0.35%.
3. The role of calcium
Ca can form Ca and Al silicate inclusions in steel, which adhere to the tool to form a thin film, have a friction-reducing effect, and prevent tool wear. The amount of Ca added is generally w(Ca)=0.001%~0.005%.
4. The role of phosphorus
P is added to sulfur-containing free-cutting steel to dissolve it in ferrite, causing strengthening and embrittlement to improve its cutting performance. In order to prevent "cold brittleness", w(P) is specified to be ≤0.15%.
The addition of these elements can also improve the surface quality of the workpiece and extend the service life of the tool.

If you need more detailed information, it is recommended to consult us for detailed information on the specific specifications and uses of these alloy steel bars.

Product Detail

Free-cutting steel is mainly used to make instruments, watch parts, automobiles, machine tools and other machines with small stress but strict requirements on size and roughness; standard parts with strict requirements on dimensional accuracy and roughness, but relatively low requirements on mechanical properties, such as gears, shafts, bolts, valves, bushings, pins, pipe joints, spring seats and machine tool screws, plastic molding molds, surgical and dental surgical instruments, etc.

Main Application

1.Fluid / Gas delivery, Steel structure, Construction;
2.ROYAL GROUP ERW/Welded round carbon steel pipes, which with Highest quality and strong supply ability are widely used in Steel structure and Construction.

Note:
1.Free sampling, 100% after-sales quality assurance, Support any payment method;
2.All other specifications of round carbon steel pipes are available according to your requirement (OEM&ODM)! Factory price you will get from ROYAL GROUP.

Size Chart

Process of production

molten iron magnesium-based desulfurization-top-bottom re-blowing converter-alloying-LF refining-calcium feeding line-soft blowing-medium-broadband conventional grid slab continuous casting-cast slab cutting One heating furnace, one rough rolling, 5 passes, rolling, heat preservation, and finishing rolling, 7 passes, controlled rolling, laminar flow cooling, coiling, and packaging.

Product Inspection

Transportation

Transportation: Express (Sample Delivery), Air, Rail, Land, Sea shipping (FCL or LCL or Bulk)

FAQ

Q: Are u a manufacturer?

A: Yes, we are a manufacturer. We have our own factory located in Daqiuzhuang Village, Tianjin City, China. Besides, we cooperate with many state-owned enterprises, such as BAOSTEEL, SHOUGANG GROUP, SHAGANG GROUP,etc.

Q: Can I have a trial order only several tons?

A: Of course. We can ship the cargo for u with LCL serivece.(Less container load)

Q: Do u have payment superiority?

A: For big order, 30-90 days L/C can be acceptable.

Q: If sample free?

A: Sample free, but the buyer pays for the freight.

Q: Are you gold supplier and do trade assurance?

A: We seven years cold supplier and accept trade assurance.We will usually satisfy our respected shoppers with our superior good quality, fantastic selling price and good company due to we're a lot more expert and far more hard-working and do it in cost-effective way for Professional China HRB400 HRB500 Hrb500e Deformed Steel Rebar Round Bar Construction Reinforcing Iron Metal Hot Rolled Round Square Stainless Carbon Steel Flat Corrugated Tmt Bar, Are you still on the lookout for a good quality product that is in accordance together with your very good organization image while expanding your item range? Consider our quality merchandise. Your choice will prove to be intelligent!
Professional China China Steel Bar and Rebar, If you need to have any of our merchandise, or have other items to be produced, make sure you send us your inquiries, samples or in depth drawings. Meanwhile, aiming to develop into an international enterprise group, we look forward to receiving offers for joint ventures and other cooperative projects.