The function of preheating welding

　　Preheating means a process that heat weldments in whole or in weld areas before welding. Particularly good material for welding high strength level, hardening tendency of steel, thermal conductivity, thickness larger weldments, and when the ambient temperature is too low,welding zone often requires butt to warm up before welding.

　　The purpose of preheating is to reduce the speed of the cooling of the welded joints and preheating temperature. It can be seen from the table, warm-up can reduce the cooling rate, but did not influence the time to stay in the high temperature, which is very desirable. So when welding steel with a hardening tendency, to reduce the cooling rate decreases the hardening tendency of the main process measures, is to warm up, rather than increase the energy input.

　　Check www.tjxysteel.com for more info

评论

发表评论

此博客中的热门博文

The main reason for the porosity of submerged arc welding seam

 Submerged arc welding technology is the welding process of SSAW steel pipe and LSAW steel pipe. During the welding process, in addition to insufficient penetration, burn-through and poor formation caused by improper welding process parameters, there will also be pores, slag inclusions, cracks, etc. Defects. This article mainly introduces the main reasons and preventive measures for porosity in submerged arc welding seams. (1) In the process of steel rolling or hot stamping and coiling, the oxide scale formed or fallen off, as well as the positioning welding slag shell, the carbon arc gas created flying slag, etc., are trapped in the flux, which will also cause pores in the weld. Preventive measures: ①The oxide skin that falls off during the process of coiling and bending should be cleaned or blown off with compressed air before assembly and welding to prevent it from being caught in the assembly gap or falling into the groove. ②The surrounding of the welding site should be clean t...
阅读全文

Standard for Choosing Oil Casing Pipe Manufacturers

 　　There are many standards for selecting oil casing manufacturers, which can be divided into short-term standards and long-term standards according to the length of time. The short-term standards for selecting oil casing manufacturers mainly include product quality, price level, timely delivery and overall service level. 　　1. Product quality 　　The quality of the purchased oil casing meets the requirements of the purchasing unit is a condition that the purchasing unit must consider when purchasing the oil casing. Poor quality and low price casing products have lower procurement costs, but will lead to an increase in the total cost, but if the quality is too high, it will far exceed the production requirements, which is also a waste. Therefore, the quality requirements of the oil casing in the procurement The production needs of the enterprise must be consistent, and the requirements are too high or too low are not appropriate. 　　2. Lower cost 　　A lower purchase price is an importan...
阅读全文

How to distinguish between ERW steel tube and seamless steel tube?

　　Today, Great Steel Pipe will tell you how to distinguish the ERW steel pipe and seamless steel pipe. 　　 ERW Steel Pipe 　　ERW is a specific type of welding process that is used to produce welded steel pipe, such as ERW steel pipe. Seam welding is commonly used during the manufacturing of round, square and rectangular steel tubing. The steel strip is unwound from coils and side-trimmed to control width and condition the edges for welding. The strip then passes through a series of contoured rollers which cold-form the material into a circular (square or rectangular) shape. The edges are forced together under pressure as a butt joint and then welded by heating the material to temperatures above 2000° F. The flash weld that has formed is now removed from the outside diameter of the tube. Once the weld has been tested the tube then passes through a series of sizing rolls to attain its precise finished size, after which the tube is then straightened and cut to length. 　 　Seamless Ste...
阅读全文