- Country of manufactureChina
65Mn Coal mill steel bars are generally used in coal chemical industry (coal to methanol, coal to ethylene glycol) and other users who need coal mill to make coal water slurry.
二、Rainbow 65Mn Technical Agreement for Steel Bar of Coal Mill
According to the field application requirements of steel rod of coal chemical rod mill, the technical agreement of steel rod of coal chemical rod mill is formulated as follows.
1、Coal chemical rod mill steel rod material:
GB/T699 - 1999 Raw Material Implementation Standard: GB/T699 - 1999
65Mn Material: 65Mn
2、Technical requirements for steel bars of coal chemical rod mills:
The steel rod of coal chemical rod mill (hereinafter referred to as "grinding rod") is specially used to grind coal in coal mill of gasification workshop to prepare coal water slurry. During the use of the grinding rod, it is not allowed to have problems such as fracture and bending which affect the normal grinding demand. Considering the problem of wear resistance, the grinding rod must have high hardness to ensure its wear resistance. Specifically, the following indicators should be achieved:
2.1、 HRC45—55（HB420 - - 560），10mm以上。The surface hardness of the grinding rod is between HRC 45 - 55 (HB420 - 560), and the hardening layer is more than 10 mm.
2.2、 The bending degree of grinding rod is less than 0.3% . During normal operation, the bending degree should not exceed the standard seriously, which will affect the output of mill and the quality of coal slurry.
2.3、When the broken rod rate of grinding rod is less than 1% and the broken rod rate is between 1% and 3% , the supplier will replace the broken rod free of charge. More than 3% of the broken rod will need to be returned and compensated for the related losses.
2.4、The impact value AK > 12j/cm_of the grinding rod is the standard sample with no notch at room temperature.
2.5、In order to guarantee the quality of grinding rods, 65Mn raw materials must be purchased from large and qualified steel mills in China.
2.6、In order to ensure the quality of grinding rods, suppliers must straighten, temper and heat treatment the grinding rods, and pass the fall destructive test.
2.7、±1mm。The grinding rod needs to be supplied in fixed length. It requires the sawing machine at both ends to cut before heat treatment. The end surface should be smooth and not oblique. The two ends should be grinded with R radian, length deviation ( + 10 mm) and diameter deviation ( + 1 mm).
2.8、The surface of the grinding rod shall be smooth and smooth, and there shall be no visible defects such as over burning, cracks, obvious burrs, lack of meat, etc. Packing should be neat and uniform for easy stacking. Different specifications should not be mixed and bundled.
2.9、Before leaving the factory, the chemical composition, surface quality, hardness distribution, straightness, diameter and length deviation must be tested and the product qualification certificate must be presented.