38results about How to "Improve ovality" patented technology

A method for making an optical fiber preform having an ultimately low PMD (Polarization Mode Dispersion) through improvement of ovality is provided. This method has several collapse steps for collapsing an optical fiber preform having a clad / core deposition layer formed in a preform tube in which a rate of collapse is 0.01-0.06 mm / min at each collapsing step. By using this method, ovality and PMD of the optical fiber preform may be improved.

The invention relates to a machining process of a high-strength steel coil pipe. The machining process of the high-strength steel coil pipe sequentially comprises the following steps of blanking, edgemilling and beveling, pre-bending, three-roller type plate rolling machine roller bending, straight seam welding and ring welding; before the plate rolling machine roller bending is carried out, theresilience of a steel plate is measured firstly, then the pipe coiling diameter is calculated when an actual pipe forming is carried out, the total lower displacement amount of an upper working rolleris calculated in the pipe coiling forming process, the pass displacement of the upper working roller is determined, and the pipe coiling machining is completed through a plurality of plate rolling; the pass displacement of the upper working roller is gradually decreased, and the first-pass displacement amount accounts for 50% or above of the total lower displacement amount, and the first three pass total displacement finishes 90% or above of the total lower displacement amount, and the upper working roller is basically in place when at least the antepenultimate pass is carried out. Accordingto the process, the displacement of the working roller can be effectively controlled, so that a high-strength steel plate with a proper size can prepare a dredging pipe with good straightness on a plate rolling machine, the gap of a pipe body does not exceed 3 mm at the end of the plate rolling, and welding can be carried out without circle rolling is performed, and the ovality of the pipe body isless than or equal to 2 mm.

The invention discloses a precise plastic forming method for a deep cup-shaped thin-walled part. Composite spinning forming process is used for processing. First calculate the size of the sheet blank with a large thickness, then use deep drawing and spinning to obtain thick-walled shallow cup-shaped parts, use flow spinning to obtain thin-walled deep cup-shaped parts, and use trimming and spinning to trim the mouth of the part and use The lathe cuts the bottom thickness of the part, resulting in a precisely formed, thin-walled, deep cup-shaped part. Compared with the stamping and deep-drawing forming process and the cutting process method, the forming method of the present invention effectively reduces the number of tooling and improves the quality indicators such as processing efficiency and part forming accuracy.

The invention discloses a preparation process of an anti-CO2-corrosion oil well pipe with a steel grade of less than 150ksi produced by a CPE unit. The process comprises the following steps: smelting each component by virtue of a converter according to the mass percentage proportion of each component, and performing continuous casting and continuous rolling on molten steel which is smelted by the converter to prepare a pipe billet, wherein the pipe billet comprises the following components in percentage by mass: 0.13-0.23% of C, 0.11-0.41% of Si, 0.8-1.0% of Mn, 5.0-6.0% of Cr, 0.05-0.45% of Mo, 0.02-0.04% of Al and the balance of Fe and inevitable impurities, and the total mass percentages are 100%. A steel pipe rolled by virtue of the process disclosed by the invention is good in surface quality and high in size precision, the anti-collapse performance of a pipe body can be effectively improved, the improvement of the anti-CO2-corrosion performance of the steel pipe can also be facilitated, the mechanical performance of the steel pipe can reach less than 150ksi, and the steel pipe is suitable for mining application of deep wells and ultra deep wells.

The invention provides a production method of an anticorrosion wear-resistant stainless steel HFW welding pipe with an outer diameter of 108-660.4mm, According to the method, the welding pipe is molded and sized by adjusting molding and sizing four-roll rigid rack equipment, oval precision of the welding pipe is up to + / -0.2mm and straightness of the welding pipe is up to 0.2mm / m; welding spots are protected by argon in a high frequency welding process of the welding pipe; a heat treatment temperature control range of welding seams of the welding pipe is between 800-900 DEG C, the welding seams and heat affected zone parts are subject to normalizing heat treatment and heat preservation time is 30-60s; pipe body positions at two sides of the welding seams are cooled by circulating water during air cooling, temperature is transferred to the welding seam positions of the pipe body of the welding body, overhigh temperature of the welding seams before the welding seams enter a water cooling section is prevented, and welding quality is not affected by structural transformation. The production method has the beneficial effects that the welding pipe produced by the method has better anticorrosion performance and magnetic conductive property, the straightness and ovality of the welding pipe are improved by 30%, equipment fault rate is reduced to 0.3% from 3%, service life is doubled, and the length of a one machine conveyor belt is improved to 6000m from 3000m.

The invention belongs to the technical field of multi-roller straightening of seamless steel pipes, and in particular relates to a method for setting the flattening amount of straightening rollers of super-large-diameter seamless steel pipes, comprising the following steps: calculating the maximum elastic-plastic flattening amount δ of steel pipes m and the maximum elastic flattening amount δ t ; According to the corresponding relationship between the wall thickness of the steel pipe and the maximum allowable flattening amount, the maximum allowable flattening amount δ of the steel pipe is obtained a ;Maximum elastoplastic flattening amount δ m and the maximum allowable flattening amount δ a For comparison, the smaller value of the two is used as the flattening amount δ of the intermediate roller 2 , the flattening amount δ of the entrance roller 1 =k 1 δ 2 , the flattening amount δ of the exit roller 3 =k 2 δ 2 ;According to the principle that the actual flattening amount of the thin-walled pipe and the thick-walled pipe meets the principle, the actual flattening amount of each pair of straightening rollers is determined, and then the purpose of differential adjustment of the flattening amount of the straightening rollers is realized by means of the pressing system. The invention can effectively improve the ellipticity of the steel pipe after straightening and improve the straightening precision of products by setting the flattening amount of the straightening rollers. The invention is used for setting the flattening amount of the straightening roller.

The invention relates to an unclear root welding process for a fan tower tube section. The specific steps include: S1, groove opening of the ring seam of the tube section; S2, a positioning ovality adjusting device; S3, grouping two adjacent tube sections ; S4, inner groove welding; S5, outer groove welding; S6, remove the outer locking mechanism. The invention has the following advantages: before the grouping, the ovality adjusting device is used to complete the rounding treatment of the two cylinder sections, so as to improve the accuracy of the grouping, at the same time, the welding quality is ensured, the operation steps of the spot welding of the grouping are omitted, and the internal stress concentration is avoided. Improve overall weld strength.