1. To reduce and eliminate the stress concentration of the lining plate, the specific methods are as follows: during casting, the riser and cold iron are used together to reduce the temperature difference of each part of the casting; Improve the yielding of mold and core to reduce the resistance during shrinkage; After casting, artificial aging, natural aging, vibration aging and other methods are used to eliminate the existence of residual stress in the casting.
2. During casting, the chemical composition shall be reasonably adjusted and strictly controlled to make the composition within the standard without exceeding the tolerance.
3. Generally, it is not allowed to carry out defect repair welding and other flame heat treatment on the surface of the lining plate after tempering treatment; If repair welding is necessary, it shall be preheated before welding, generally 150 degrees. When welding, pay attention to the welding sequence, weld symmetrically, and always maintain the temperature of the base metal during the welding process. After welding, it shall be heated continuously, covered with heat preservation, slow cooling and reduce the cooling rate, so that cracks will not appear in general. Small cracks on the surface are usually polished with a hand-held grinder until the cracks are completely polished off.
4. Increase the casting fillet of the lining plate to prevent excessive stress concentration.
5. Moderately increase the wall thickness at the bolt hole.
6. During lining plate casting, the position of riser shall be reasonably arranged to keep it away from the position of bolt hole.
7. The outer arc shape of the lining plate shall be in accordance with the size requirements of the drawing, and serious out of tolerance is not allowed, so as to make the lining plate surface closely fit the inner wall surface of the coke tank without gap.
8. Expand the size of the bolt hole, increase the gap between the bolt and the bolt hole wall after installation, and prevent the bolt from preventing or hindering the free expansion and contraction of the lining plate after installation.
9. The overall length and width of the lining plate shall be controlled according to the negative difference of the drawing to prevent the gap between the lining plate and the lining plate from being too small after assembly.