More than ten years ago, when I had just touched the seamless steel tube, I thought the steel pipe was very simple. Is there a hole in the middle of the round steel, what is difficult. But as I work step by step further, I found the cold draw steel pipe is not so simple, there are a lot of knowledge and learning, today to share this calculation method of cold drawing seamless steel tube cold rolling and drawing force of teaching, is an article I wrote many years ago, today is to share out a role, I hope to study this person comments.

制定管材冷轧冷拔生产(见管材冷轧冷拔机组)的工艺流程及变形规程。在管材冷轧冷拔机组中，在产品投产以前必须对它的生产工艺流程、变形参数和加工设备选择等有一个明确的规定，作为组织生产和进行操作的依据，这项工作就是编制工艺程序表。根据所采用的冷加工方法，工艺程序表可分为拔制表(采用冷拔变形)和轧制表(采用冷轧变形)以及轧制和拔制表(采用冷轧冷拔两种方式变形)，由于管材冷轧冷拔生产特点是多工序和循环性，而且品种很多，为了使生产能合理和有秩序地进行，编制工艺程序表是很重要的。工艺程序表的内容包括有：管料尺寸，变形方式和道次，每道次的变形量及变形后管子尺寸，选用的加工设备、辅助工序和工模具类型等。编制工艺程序表时，除根据材料加工特性和管子技术条件外，还必须考虑具体的生产条件。各冷拔冷轧机组都有根据自己生产条件制定的工艺程序表，并且在生产实践中不断地进行修改和完善。

The process flow and deformation regulation of cold - drawn tube production (see tube cold rolling and cold drawing unit) are formulated. In pipe cold rolling and cold drawing unit, there must be a clear regulation on its production process, deformation parameters and processing equipment before it is put into production. As a basis for organizing production and operation, this work is to compile process schedule. According to the cold processing method, process chart can be divided into pull tab (deformation by cold drawing and rolling (table) by cold rolling and rolling) and pull tab (deformation by cold rolling and drawing in two ways), because the production characteristics of cold rolling and drawing of tube is multi process and circulation, and many varieties, in order to make the production reasonable and orderly, the preparation of program is very important. The contents of the process schedule include: pipe size, deformation mode and pass, deformation per time and size of pipe after deformation, selection of processing equipment, auxiliary process and mold type. In addition to the processing characteristics of the material and the technical conditions of the tube, the specific production conditions must be considered. All cold - drawn cold rolling mills have the process schedule according to their own production conditions, and they are constantly modified and perfected in the production practice.

冷加工方式的配置     按冷轧和冷拔使用情况，方式配置可有单一冷轧、单一冷拔和冷轧冷拔结合3种方案。

Cold rolling and cold drawing are used in cold rolling and 3 schemes can be combined with single cold rolling, single cold drawing and cold rolling cold drawing.

(1)单一冷轧方案。和冷拔相比，冷轧变形时应力状态好，道次变形量大，可减少中间工序并缩短生产周期，能降低消耗和降低成本，适宜加工塑性差的高合金钢管和难变形的有色金属。其缺点是生产力低，生产灵活性较小。

(1) single cold rolling scheme. Compared with cold drawing, cold rolling has good stress state and large pass deformation. It can reduce intermediate processes and shorten production cycle, reduce consumption and reduce cost, and is suitable for processing high alloy steel tubes and non-ferrous metals with poor plasticity. Its disadvantages are low productivity and less flexibility in production.

(2)冷轧冷拔结合的方案。是管材冷加工的合理方案，冷轧冷拔相结合可发挥冷轧变形量大和冷拔生产灵活的优点，以减少工序、缩短生产周期、提高生产力和扩大品种。采用冷轧冷拔结合方案时，通常是管料先在冷轧机上轧到定壁或定壁前的某个道次，然后进行拔制，直至成品道次。

(2) the combination of cold rolling and cold drawing. It is a reasonable plan for cold processing of pipes. The combination of cold rolling and cold drawing can bring into play the advantages of large cold rolling deformation and flexible cold drawing production, so as to reduce process, shorten production cycle, increase productivity and expand varieties. When cold rolling and cold drawing are combined, the pipe material is usually rolled on the cold rolling mill to a certain pass before or before the wall is fixed, and then pullled until the finished product passes.

(3)单一冷拔方案。由于冷拔的道次变形量较小，变形道次多，中间工序多，生产周期长，金属及辅助材料消耗大，单一冷拔方案不是最优方案。但拔管机结构比冷轧机简单，投资少，操作容易掌握，工具的制造和更换方便，生产灵活性大，生产力也较高。故采用单一冷拔方案来加工碳钢、低合金钢管和一般有色金属管在实际生产中有广泛的应用。

(3) a single cold drawing scheme. Due to the small deformation of cold drawing, there are many deformation passes, many intermediate processes, long production cycles, and large consumption of metal and auxiliary materials. The single cold drawing scheme is not the best one. But the structure of the pipe pullout machine is simpler than the cold rolling mill, the investment is less, the operation is easy to master, the manufacture and replacement of the tool is convenient, the production flexibility is big, and the productivity is high. Therefore, a single cold drawing scheme is used to process carbon steel, low alloy steel tube and nonferrous metal tube in practical production.

管料尺寸的选择

Selection of pipe size

在冷加工管材生产中，管料的尺寸(直径和壁厚)决定着变形道次、成品管尺寸精度和表面质量。在能保证成品管质量的前提下尽可能选用接近成品尺寸的管料。管料的最小壁厚应能保证管料和成品管的壁厚差(即总减壁量)能消除热轧管表面的螺纹道、划道等表面缺陷，改善壁厚不均，以获得尺寸公差和表面质量都符合要求的管材。在冷拔管生产中，冷拔的最小总减壁量一般取0.5～1mm。对成品管质量(尺寸精度、表面质量)要求高时也可以将总减壁量取大一些。在可供应条件下，管料的直径一般比成品管的直径大5～20mm。主要是考虑减径量与减壁量的关系，即变形时有一定的减壁量必定有相应的减径量，才能保证顺利实现金属变形。

In the production of cold processed pipes, the size (diameter and wall thickness) of the pipe determines the size accuracy and surface quality of the deformation channel, the finished product pipe. On the premise that the quality of the finished product can be guaranteed, the pipe material close to the finished product size can be selected as much as possible. The minimum wall thickness of the pipe should ensure the wall thickness difference between the pipe and the finished product, that is, the total wall reduction. It can eliminate the surface defects of the hot rolling pipe surface, such as screw thread, stroke and so on, and improve the uneven wall thickness, so as to get the pipes that meet the requirements of dimensional tolerances and surface quality. In the production of cold drawn tube, the minimum total wall reduction of cold drawing is usually 0.5 ~ 1mm. When the quality of the finished product (dimensional precision, surface quality) is high, the total wall reduction can also be increased. Under the conditions of supply, the diameter of the pipe is 5 to 20mm larger than the diameter of the finished tube. The relationship between reducing diameter and wall reduction is mainly considered. That is to say, there is a certain reduction of wall volume during deformation, so there must be a corresponding reduction in diameter to ensure smooth metal deformation.

选择冷轧管料与冷拔的原则基本相同，但在确定管料和中间管尺寸时则要考虑满足冷轧机孔型系统的要求。

The principle of selecting cold rolling pipe and cold drawing is basically the same, but when determining the size of pipe and middle pipe, it is necessary to meet the requirements of the pass system for cold rolling mill.

道次变形量的选择即确定每个加工道次的变形程度(断面压缩率、延伸系数)、减径量和减壁量。在条件允许时，应选取大的道次变形量，以减少加工道次。选择冷轧管机道次变形量时要考虑轧机主要部件强度、材料塑性、对管材的质量要求等。在实际生产中管材的尺寸精度、表面状态以及工具的寿命等常成为限制道次变形量的因素。为了保证产量和质量，成品道次的变形量应取小一些。在多辊式冷轧管机上道次变形量(特别是减径量)比二辊式冷轧管机的小。

The selection of the deformation of the channel is to determine the degree of deformation of each processing Road (section compression rate, elongation coefficient), reducing the diameter and reducing the wall. When the condition is allowed, a large amount of deformation should be selected to reduce the processing path. The strength of the main parts of the rolling mill, the material plasticity and the quality of the pipe should be taken into consideration when selecting the secondary deformation of the cold rolling mill. In actual production, the size accuracy of the pipe, the surface state and the life of the tool are often the factors that restrict the deformation of the channel. In order to ensure the production and quality, the amount of deformation of the finished product should be smaller. The deformation of the multi roll cold rolling mill (especially the reducing diameter) is smaller than that of the two roll cold rolling mill.

选择冷拔机道次变形量的影响因素有：金属的冷加工性能(包括金属的强度和塑性)、管身强度(拔制时不能出现拔断现象)、拔管机能力以及选用的拔制方式(见管材冷轧冷拔)和模具类型(见冷拔管工具)。在选择拔制道次变形量时还应考虑的因素有：连拔道次(道次中间不经热处理)的多少，热处理、酸洗、润滑质量的好坏。

The influencing factors of cold drawing machine pass deformation are: cold working properties of metals (including the strength of the metal and plastic), tube strength (not drawing when the pull off phenomenon), pulling machine ability as well as the selection of drawing mode (see cold rolling and drawing of tube) and mold type (see drawing tool). The factors that should be taken into consideration when selecting the deformation of the pass are: how much the continuous trip passes (the intermediate part is not heat-treated), the quality of heat treatment, pickling and lubrication.

变形道次的确定    变形道次按下式确定：

The determination of deformed channel times of deformed channel determination: