3 results about "Reduction ratio" patented technology

The invention relates to carburizing steel and a production method of carburizing steel parts. The carburizing steel comprises the following chemical components in percentage by mass: 0.15%-0.25% of C, 0.30%-0.80% of Mn, less than or equal to 0.035% of P, 0.020%-0.040% of S, 0.90%-1.40% of Cr, 0.20%-0.40% of Mo, 0.020%-0.050% of Al, 0.001%-0.003% of B, 0.10%-0.20% of Cu, less than or equal to 0.04% of V and the balance of Fe and inevitable impurities. Wherein O is smaller than or equal to 12 ppm, and N is 150-200 ppm. In the carburizing steel pretreatment step of the production method of the carburizing steel part, at least two tensile samples are taken from round steel; the carburizing steel is adopted as the round steel; carrying out phosphating treatment on the tensile sample; the tensile samples are divided into two groups for tensile testing, and after the section reduction ratio Z1 / Z2 of the two groups of tensile samples is calculated, the remaining part of the round steel is subjected to staged treatment. The tensile test method does not need complex equipment and is simple to operate.

The present application relates to a kind of micro-tension load distribution methods for continuous rolling mill group, the continuous rolling mill group includes several racks, including the following steps: the moment of force of the each rack is obtained, reduction ratio and roll diameter;According to the free load torque of the first end rack, the moment of force of the each rack, the reduction ratio of the each rack and the roll diameter of the each rack, the free load torque of the each rack except the first end rack is calculated;According to the free load torque of the each rack and the torque arm length of the each rack, the rolling load of the each rack is calculated;Based on free rolling torque, accurate and reasonable rolling load distribution is carried out, which ensures the stable tension rolling between the racks of continuous rolling mill group, effectively avoids the phenomenon of material stack pulling between the racks, thereby effectively improves the quality of product, and reduces the dependence on operator's technology.

The present invention relates to the technical field of steel rolling, and particularly to a rolling method for large-section grinding ball steel billets, which includes the processes of billet heating, blooming rolling and continuous rolling; the blooming rolling adopts 11 passes or 13 passes of rolling. After the first pass of rolling, the steel is not turned over, and the second pass of rolling is carried out along the rolling direction of the first pass; after the second pass of rolling, the steel is turned over by 90°, and then the third pass and the fourth pass of rolling in the same direction are carried out. After the fourth pass of rolling, the steel is turned over by 90° again; and so on, the steel is turned over by 90° after every two passes of rolling in the same direction; the reduction ratio per pass of rolling is 10% - 30%, and the maximum reduction ratio of the billet in a single direction is 40% - 45%. By adopting the blooming rolling method of the present invention, the coarse grains inside the billet can be effectively broken, playing the role of grain refinement; the rolling deformation penetrates into the core of the billet, reducing the influence of the central porosity of the billet on the structure and properties of the finished steel.