SAE8660 Square Cutter Chain

SAE8660 Square Cutter Chain

The chemical composition mass percentage of the steel is: C 0.56~0.64, Si 0.15~0.35, Mn 0.75~1.0, P≤0.035, S≤0.040, Al 0.025~0.035, Ni 0.40~0.70, Cr 0.40~0.60, Mo 0.15~0.25, the allowance is Fe, The specifications of hot rolled sheet are (1.6~8.5) × (960~1500) mm. 100t converter smelting, LF refining furnace refining, thin slab continuous casting and rolling, laminar cooling, coiling, slow cooling down line. The superheat of molten steel during continuous casting is 15 ~ 45℃, and the drawing speed of continuous casting is 3.0 ~ 4.5m/min. The temperature of casting billet into soaking furnace is ≥800℃, the final rolling temperature of hot rolled sheet is 850 ~ 950℃, the coiling temperature is 580 ~ 750℃, and the steel coil is gently cooled after being coiling. The SAE8660 hot rolled thin steel plate has weak center segregation, low band structure grade, good surface quality, thin oxide sheet thickness, low incidence of cracks on the edge and surface, and good homogeneity of microstructure and properties.

Mechanical characteristics:

High hardness and high wear resistance can be obtained after heat treatment, which is mainly used for manufacturing various kinds of products

Tools, cutting tools, molds and measuring tools.

Weldability is widely used as deep drawing parts such as automobiles, cans..... 20G is the main material for making ordinary boilers. In addition,

Low carbon steel is also widely used as carburizing steel for machinery manufacturing.

The SAE8660 hot-rolled sheet steel has the chemical composition (mass percentage content) of: C 0.56~0.64, Si0.15~.35, Mn 0.75~1.0, P≤0.035, S≤0.040, Ni 0.40~0.70, Cr 0.40~0.60, Mo 0.15~0.25, the allowance is Fe, The specifications of hot-rolled sheet are (1.6~8.5) × (960~1500) mm.

The production process of SAE8660 hot rolled sheet comprises the following steps:

Converter smelting →LF furnace refining → thin slab continuous casting and rolling → laminar cooling → coiling → slow cooling of steel coil down the line, the process parameters are as follows:

Converter and LF refiner produce high quality steel with high cleanliness.

Thin slab continuous casting and rolling produce slab thickness of 60 ~ 90mm. The superheat of molten steel during continuous casting is 15 ~ 45℃, the pulling speed of continuous casting is 3.0 ~ 4.5m/min, the thickness of continuous casting slab is thinned from 70mm to 65 ~ 60mm by pressing the liquid core, and the temperature of continuous casting slab after the fan section of continuous casting machine is maintained between 850 ~ 950℃.

Continuous casting slab into soaking furnace temperature ≥800℃, into the tunnel soaking furnace heating, insulation.

The continuous casting slab is rolled into (1.6 ~ 8.5) ×(960 ~ 1500)mm hot rolled sheet with a seven-stand finishing continuous rolling mill, and the final rolling temperature of the hot rolled sheet is 850 ~ 950℃.

The hot rolled sheet is rolled into steel coils at a temperature of 580 ~ 750℃.

After the steel coil is taken off the line, it is piled for slow cooling.

Compared with the prior art, the SAE8860 hot-rolled sheet production process provided by the above technical scheme has the following advantages:

① The production of high-quality SAE8660 alloy tool steel in China has broken through the technical blockade of foreign products and realized the substitution of domestic imports.

② Continuous casting and rolling equipment is used for production, avoiding the process of slow cooling of medium carbon alloy steel continuous casting slab off the line, and the furnace can be loaded at a temperature above 800 ° C, reducing energy consumption and saving production costs. The thickness of continuous casting billet is between 60 ~ 90mm, compared with the thickness of conventional slab 210 ~ 230mm, the degree of columnar crystal is weakened and the element composition is more uniform. Continuous casting equipment can also achieve liquid core compression, better improve the center segregation, product specifications can achieve as thin as 1.6mm thickness specifications of production.

③ Continuous casting slab can directly enter the soaking furnace from the continuous casting machine, without slow cooling or downline, avoiding the surface cracks of the slab caused by excessive cooling in these processes; In addition, the furnace temperature is higher, there is no need to start heating from low temperature, thin the surface of the iron oxide sheet, but also reduce the slab heating energy consumption.

④ The product quality is high, mainly in: for thin specification products below 3mm, there is still a good shape; The thickness of the oxide sheet on the surface of the steel plate is thin, generally below 12μm, there is no edge or surface crack, the color is bright and uniform, and the surface quality is high. The internal segregation is weak, the banded structure is below 1.5 grade; High uniformity of microstructure and mechanical properties.

Application Area

1. Automobile manufacturing: Used in automobile chassis, body structure, steering system, suspension system, transmission system and other parts, so that the car has better reliability and safety.

2. Aircraft aviation: used in aviation structure, engine parts, flight control system and other parts, which can reduce the weight of the aircraft and improve its flight performance.

3. Ship manufacturing: Used for hull, bridge, ship transmission system and other parts, with excellent corrosion resistance and strength, can enhance the durability of the ship and navigation safety.

4. Construction machinery: used for excavators, loaders, bulldozers, tampers and other key parts of construction machinery, can improve its carrying capacity and service life.

5. Petrochemical equipment: used for pressure vessels, storage tanks, pipelines and other parts of petrochemical equipment, which can withstand extreme conditions such as high temperature, high pressure and corrosion wear to ensure the stable operation of equipment.