Preparation method of LD steel cold roll ejector for small-pore stainless seamless pipe

Abstract

The invention provides a preparation method of an LD steel cold roll ejector for a small-pore stainless seamless pipe. The preparation method includes: blanking, preheating, rough machining with lathe, fine machining, thermal treatment and precision machining. By modifying feeding amount and uniform reserving allowance parameters of outer conical surface in the rough grinding procedure in fine machining, feeding amount parameters in the fine grinding procedure, and process parameters in the super grinding procedure of precision machining, the preparation method is reasonable in process, simple and practical.

Description

technical field [0001] The invention relates to the production field of special cold-rolled plugs for producing seamless steel pipes in metallurgy and machinery industries, and in particular to a preparation method for cold-rolled plugs for small-diameter stainless steel seamless pipes. Background technique [0002] Seamless steel pipe is a common metallurgical metal product. Small-diameter alloy seamless pipe is a high-end product in seamless steel pipe. The aperture (diameter of the inner hole of the steel pipe) is generally less than 20mm. It is used in special fields, and the technical content and production difficulty are relatively high. In the production of seamless steel pipes, cold deformation processing is the main production process; cold rolling production is a widely used cold deformation processing production method. [0003] The two-roller periodic cold-rolling mill is currently the most commonly used cold-rolling equipment for seamless steel pipes. The plug i...

AI Technical Summary

Problems solved by technology

[0011] (1) Machining by digital machining center: Machining by digital machining center is to use the existing digital machining center to process the fixed-cut round steel billet on the machining center with multi-process and multiple cutting (excluding heat treatment) , has the advantages of high processing precision, fast speed, and guaranteed yield, but the disadvantage is that the processing cost is high and the investment in equipment is large.

[0012] (2) CNC machine tool processing: CNC machine tool processing is to use a single CNC machine tool (lathe, grinder, etc.), multiple clamping, multiple processing, sequential processing until forming (excluding heat treatment), with high processing accuracy, relying on the program The control does not require a profiling template (profiling) as a processing benchmark, but the disadvantage is that it is highly dependent on the program, and the operation of programming and inputting the program is cumbersome and error-prone;

[0013] (3) Ordinary machine tool processing: it is ordinary machine tools (lathes, profiling lathes, planers, grinders, etc.) with various machine tools, multiple clamping, multiple processing, sequential processing until forming (excluding heat treatment), with low equipment requirements, It can realize multi-station (process) coordination, easy processing and other advantages. The disadvantage is that the profiling model (pattern) is used as the processing benchmark, which has high requirements for the profiling model (profiling) and relatively high technical requirements for machine tool operators. High, and low processing efficiency, low yield

[0015] 1) Due to the slender shaft and curved shape of the cold-rolled plug, the ordinary processing equipment and process methods cannot meet the processing requirements of LD steel, that is, the working length-to-diameter ratio is between 25-40, and the average is more than 30, which belongs to thin Long-axis workpieces are difficult to process on ordinary lathes. At the same time, the busbar of the head is curved, and the tool holder cannot be used. The rigidity is poor during cutting, and it is easy to vibrate, bend, deform, and difficult to process. The commonly used CF7112 copying lathe has a complex structure , high cost, bulky, can only be processed by adding a profiling device to ensure the processing quality, and the cutting amount is limited, the processing speed is slow, the operation is cumbersome, and the yield is low;

[0016] 2) The surface roughness is high, equivalent to 0.8, and the dimensional accuracy tolerance is ±0.01mm, so the technical requirements are very high. The final finishing can only be done by grinding machines, while ordinary cylindrical grinders can only grind continuous planes, cones Surface, grinding continuous curved surface must add profiling auxiliary device to ensure the processing quality;

[0017] 3) Both lathes and grinders need to add auxiliary profiling devices, and the commonly used rigid profiling method, due to the large size and specifications of the plugs and different curves, it is necessary to prepare multiple profiling templates (profiling templates) and the cost is high, and the profiling method belongs to Rigid contact, the mold is easy to wear, and the precision of the processed body is low, which cannot meet the technical requirements;

[0018] 4) The digital machining center has high processing precision and high efficiency, but the processing cost is higher, and the investment for one-time purchase is too high, and the daily maintenance cost after the event is not low. And there is a risk of leakage of technical data;

[0019] 5) The machining accuracy of CNC machine tools is high, and the processing efficiency is higher than that of ordinary machine tools and lower than that of digital machining centers. It does not need copying templates (patterns), but it is highly dependent on programs, and programming is cumbersome (need to calculate and measure points on continuous surfaces key nodes), error-prone when program input

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