Analysis of common surface defects of cold rolled wear-resistant plate
The common surface defects of cold-rolled wear-resistant plates can be divided into the following categories according to the different formation conditions and mechanisms:
(1) Residual attachment defects, including watermark defects, foreign bodies pressed into, etc. The watermarking defect is often produced in the lower surface of the high-speed cold rolled wear-resistant plate near the DS side, it is due to the rolling before and after the emulsion cleaning is not complete, abnormal involved in the belt cutter roll, after annealing the surface of the watermarking defect, different shapes, or strip, or block, the color is white and black, white is residual ash and salt, black is residual carbon, miscellaneous oil. Foreign matter pressing refers to the external foreign matter sticking on the surface of the wear-resistant plate through rolling, extrusion formed by the spot, line, block defects, including the oxide sheet pressing, the unit oil dripping on the surface of the wear-resistant plate or the roll surface pressing, solution, particles and other debris sticking on the surface of the wear-resistant plate;
(2) Processing deformation defects, such defects are caused by equipment failure, production process or improper operation, including stripes, stem marks, scratches, etc. The striation defect is caused by the excessive thickness of the coating, and the abrasion is caused by the surface damage caused by the contact between the wear-resistant plate and hard objects such as processing equipment during the production process.
(3) Surface hole defects are divided into three categories: loose honeycomb hole defects, irregular hole defects, crescent hole defects. The reasons for the holes can be summarized as follows: First, the unreasonable continuous casting production process leads to the inclusion defects such as subcutaneous slag rolling, slag inclusion, bubbles, needle pores, etc., which weakens the strength of the local area of the wear-resistant plate and forms holes in the rolling process. Second, the rolling production process is inappropriate, such as slab deviation caused by local area edge folding, or poor plate shape and other reasons caused by uneven sticking roll and deformation, resulting in the generation of holes;
(4) Surface rust spot defects, such defects are mainly affected by the external environment, corrosion defects caused by chemical reactions on the surface, generally yellow-brown spots, may be distributed in any part of the surface, mainly divided into massive rust, dense rust, sporadic rust. After pickling, there are residual acids on the surface of the plate, low ambient temperature, insufficient supply of compressed air, residual moisture of the leveling liquid and poor effect of the anti-rust agent may lead to rust spot defects on the surface of the wear-resistant plate.
