Wear resistant steel plate is an alloy wear-resistant layer mainly composed of Cr7C3 carbides with a volume fraction of more than 50% formed by surfacing on ordinary steel plate, heat-resistant steel plate and stainless steel plate.
Wear resistant steel plate has high wear resistance, impact resistance, deformability and weldability. It can be directly processed into engineering parts like steel plate, such as crimping deformation, cutting and drilling, so as to meet the needs of wear-resistant industries and mines.
Density ≥ 3.6 g / cm3
Rockwell hardness ≥ 85 HRC
Pressure degree ≥ 850 MPa
Fracture toughness K Ι C ≥4.8MPa·m1/2
Bending strength ≥ 290mpa
Thermal conductivity 20W / m.k
Coefficient of thermal expansion: 7.2 × 10-6m/m.K
1. The chemical composition of the high wear-resistant alloy layer has carbon content of 4 ~ 5% and chromium content of 25 ~ 30%. The volume fraction of Cr7C3 carbide in the metallographic structure is more than 50%, the macro hardness is hrc56 ~ 62, and the hardness of chromium carbide is hv1400 ~ 1800, which is higher than that of quartz in sand HV800 ~ 1200. Because the carbides are vertically distributed in the wear direction, the wear resistance is more than doubled compared with the cast alloy with the same composition and hardness.
2. Compared with several typical materials, the wear resistance is as follows:
(1) And mild steel; 20~25：
(2) And high manganese steel; 5~10：
(3) And tool steel; 5~10：
(4) And as cast high chromium cast iron; 1.5~2.5：
2. Good impact resistance: the bottom layer of wear-resistant composite steel plate is low carbon steel or low alloy. Stainless steel and other ductile materials reflect the advantages of bimetals. The wear-resistant layer resists the wear of wear media, and the substrate bears the load of media, so it has good impact resistance. It can withstand the impact and wear of high drop hopper in material conveying system.
3. Good heat resistance: the wear-resistant layer is recommended to be used under the working condition of ≤ 600 ℃. If vanadium, molybdenum and other alloys are added to the alloy layer, it can withstand high-temperature wear of ≤ 800 ℃. The recommended operating temperature is as follows: ordinary carbon steel substrate is recommended to be used under the working condition of not higher than 380 ℃; Low alloy heat-resistant steel plate (15CrMo, 12Cr1MoV, etc.) substrate is recommended to be used under the working condition of not higher than 540 ℃; The heat-resistant stainless steel substrate is recommended to be used under the working condition of no more than 800 ℃.
4. The alloy layer of wear-resistant composite steel plate with good corrosion resistance contains a high percentage of metal chromium, so it has certain rust prevention and corrosion resistance. It is used in coal chute and funnel to prevent coal sticking.
5. Strong applicability, wear-resistant composite steel plate has a wide range of specifications and varieties, and has become a commodity series. The thickness of wear-resistant alloy layer is 3 ~ 20mm. The minimum thickness of composite steel plate is 6mm, and the thickness is unlimited. Standard wear-resistant composite steel plate can provide 1200 or 1450 × 2000mm, or customized according to the drawing size according to the user's needs. Wear resistant composite steel plate is now divided into ordinary type, impact resistant type and high temperature type. It should be explained when ordering high temperature wear-resistant and impact resistant composite steel plate.
6. Convenient processing performance wear-resistant composite steel plate can be cut, leveled, perforated, bent and crimped. It can be made into flat plate, arc plate, cone plate and cylinder. The cut composite plate can be welded into various engineering structural parts or parts. The composite plate can also be heated and pressed into a complex shape with a mold. The wear-resistant composite steel plate can be fixed on the equipment by bolts or welding, which is convenient for replacement and maintenance.
7. Although the manufacturing cost is increased, the service life is increased several times, which greatly reduces the maintenance cost and shutdown loss. Its price performance is about 2 ~ 4 times higher than that of ordinary materials. The larger the material handling capacity and the more serious the equipment wear, the more obvious the economic effect of using wear-resistant composite steel plate.
When the grindability of materials is medium (slag Bond work index 20, raw meal Bond work index 10, coal Hastelloy index 75 or ton consumption of 3G / T), the normal operation time of wear-resistant parts of slag vertical mill after surfacing can reach 1800 ~ 2000 hours, the operation time of wear-resistant parts of coal vertical mill can reach more than 7000 hours, and the operation time of wear-resistant parts of raw meal vertical mill can reach more than 7000 hours When the operation time of wear-resistant parts of cement clinker vertical mill reaches more than 2500 hours and the operation time of extrusion roller reaches more than 4000 hours (after online surfacing) ~ 8000 hours (after offline surfacing), it can be considered that the wear-resistant parts after surfacing meet the expected wear performance requirements.
For vertical grinding wear-resistant parts with cast base material of high chromium cast iron or nickel hard Ⅳ, the surfacing layer shall not fall off within 3 months after the surfacing is remanufactured and put into operation.