Method for correcting C-shaped steel casting

Abstract

The invention discloses a method for correcting a C-shaped steel casting. The method comprises the following steps: preparing a steel plate according to the dimensions of a C-shaped steel casting to be corrected, fixedly welding a fixing block on the steel plate, enabling a mounting hole to be formed in the fixing block in the length direction, mounting a rotating shaft in the two ends of the mounting hole through first bearings, enabling two threaded sections with equal lengths and opposite spiral directions to be formed on the rotating shaft, mounting a threaded sleeve on each of the two threaded sections, and further arranging an arc-shaped preheating pipe used for heating the steel casting at the arc top on the inner side of the C-shaped steel casting. The method for correcting the C-shaped steel casting has the benefits as follows: large-sized correcting auxiliary equipment does not need to be used, the operation is simple, easy to carry out, safe and reliable, the C-shaped steelcasting is corrected from the two ends simultaneously, the correcting time is shortened, the correcting efficiency is higher, and the two ends are corrected simultaneously so as to ensure the consistency of the correcting forces borne by the steel casting at the two ends; besides, the dimensional welding repair quantity of the casting due to deformation is greatly reduced, the welding cost is saved, and the production cycle of the casting is shortened.

Description

technical field [0001] The invention relates to the technical field of rectification and shaping of large steel castings, in particular to a method for correcting C-shaped steel castings. Background technique [0002] The material of large thick-walled rotary high-strength steel castings is medium-high-carbon low-alloy steel, and the material mainly includes the following mass components: C: 0.30~0.35, Si≤0.6, Mn: 0.6~1.0, P≤0.025, S≤0.020, Ni≤0.4, Cr: 1.4-1.7, Mo: 0.15-0.35. The diameter of the casting is generally 5-6m, and it is divided into two halves. The single half of the steel casting is C-shaped, the maximum wall thickness is 200mm, the minimum wall thickness is 50mm, and the weight of the single half is 5t. The final mechanical properties required are: tensile strength Rm≥770MPa, yield strength Rp0.2≥525MPa, elongation ≥10%, reduction of area ≥35%, body hardness 223-300HB, room temperature impact toughness AKV≥27J. From the perspective of mechanical properties, i...

AI Technical Summary

Problems solved by technology

This practice not only increases the amount of welding, but also increases production costs such as gouging, relief grinding, and NDT testing, and there is a risk of secondary deformation after welding

Another approach in the existing technology is to increase the casting anti-deformation subsidy during the molding process, which ensures that there is no black skin phenomenon in the processing to a certain extent, but increases the consumption of molten steel, making the shape and size of the casting different from the drawing requirements Larger, it also increases the amount of processing and increases the cost of castings

In the prior art, there is also a method of setting a single layer of cross tie bars to prevent casting deformation, but actual production shows that only setting a single layer of cross tie bars has no significant effect on preventing casting deformation

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