Method for intensifying Cr-Mo alloy cast iron thin-wall cylinder liner

Abstract

The invention discloses a method for intensifying a Cr-Mo alloy cast iron thin-wall cylinder liner. A cylinder liner blank piece with a flange matched with a box body is cast by the centrifugal technology and is mechanically processed; an outward and upward bearing surface which forms a taper angle of 5-30' with the horizontal surface is processed on the lower end surface of the flange; and dedicated rolling equipment is adopted for locally intensifying and rolling the lower end surface of the flange and a transition fillet on the excircle of the cylinder liner by a rolling force. In the method, the required working procedures are few, the cost is low, and the tissue of the material of the centrifugal casting cylinder liner is even and refined; the lower end of the flange of the cylinder liner is provided with a bearing surface structure to improve the bearing capability of the cylinder liner and improve the stressed state, and the cylinder liner is easier to press when being stressedand is favorable to expansion if being heated and expanded, thereby preferably realizing effective sealing; a special rolling force and dedicated rolling fillet equipment are adopted to increase the surface prestressing force, thus being favorable for eliminating the phenomenon of stress concentration because of local processing tool marks; the bearing capability of the cylinder liner is improved; and the tearing tendency is lowered.

Description

technical field [0001] The invention relates to a production method of a cylinder liner, in particular to a method for strengthening a Cr-Mo alloy cast iron thin-wall diesel engine liner. Background technique [0002] The existing cast iron cylinder liner is generally made of Cr-Mo alloy cast iron. The structure of the cylinder liner is a cylindrical structure with a flange. The flange of the cylinder liner is matched with the engine case, and the flange is circular. structure, the upper and lower end surfaces of the flange are planes, and the transition between the lower end surface and the outer cylindrical surface of the cylinder liner is designed as a rounded structure. The production process of the cylinder liner is as follows: firstly, the cylinder liner blank is cast by ordinary casting methods such as sand casting, and then the blank is processed into a cylinder liner by grinding, machining, heat treatment and other mechanical processes. The internal structure of th...

AI Technical Summary

Problems solved by technology

The internal structure of the cylinder liner cast by ordinary casting processing methods is uneven, and it is easy to deform due to uneven force; and when the current cylinder liner is assembled on the engine case, the cylinder liner is pressed and connected by the flange On the box body, the thin-walled cylinder liner is prone to large deformation, and the connection between the flange and the outer cylindrical surface of the cylinder liner must bear large surface stress, and it is easy to crack during use

In order to increase the strength of the cylinder liner, the general method is to increase the wall thickness of the cylinder liner, which will reduce the inner diameter and volume of the cylinder liner, thereby greatly reducing the bearing capacity of the cylinder liner. Low power, small power coverage

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