· · 112 Position and function of preheating technology in welding application technology Guanfu Sun 1 , Weizhi Dai 1, 2 , Wei Zhang 1 (1. Jinggong Steel Building Group, Zhejiang 312030, China; 2. China Engineering Construction Welding Association, Beijing 100088, China) Abstract: Combining with the superficial understanding of preheating in practical engineering application, this paper expounds the preheating technology starting with its definition. Considering the current situation of insufficient understanding to preheating, this paper makes explanation and illustration of relevant point, introducing the related technical theory in simple terms. At the same time, this paper also recommends several methods to determine the preheating temperature, trying to make readers learn more about the position and function of preheating technology in welding process by combining with engineering project. t 100 , one of the most important parameters, is introduced in this article, which has an important role on the preventing of hydrogen-induced crack in strength steel welding joint. Key words: preheating; preheating process; secondary crystall- ization; methods to determine DOI: 10.7512/ j.issn.1001-2303.2017.13.07 Senior engineer; To be engaged in the development and research and application of steel structure welding application technology, and be good at the formulation of design and welding technology of large-scale complex steel structure system. There is a certain accomplishment in the welding technique of steel structure of construction steel. Strong theoretical foundation and rich practical experience. Be willing to cooperate with international coun-terparts. Weizhi Dai Email: [email protected]0 Introduction The high-required technical parameters of welding application is always used in the steel structure and manufacturing industry. These parameters are involved with basic theory and practical engineering experience. In other words, they are the combining outcomes of the basic theory and practice. For example, preheating is a very prominent representation, which plays vital role in the steel structure welding engineering. It can even be concluded that the properly application of preheating technology determines the success or failure of welding project to a certain extent! However, it is regrettable of the point that the technical content of preheating is low, which maybe because the preheating process is too common superficially. As a result, there are few studies on these parameters in welding academia and engineering, and the articles related to preheating are rare as well, causing some fuzzy understandings of the preheating technology. In fact, though the preheating is widely used and universally known, the related esoteric theory of welding applied technology is little- known. So there exists a lot of confusions in engineering practice, which inevitably produces incompetence in actual production. Thus, it can be concluded that the welding quality must be pessimistic in these confused and uncertain views. 1 Definition of preheating and relevant technical connotation ( 1 ) Definition of preheating. Preheating is the process of heating the welding joints to a temperature above the air temperature before welding. The process of reheating during the welding process also belongs to the category of preheating technology. ( 2 ) Relevant technical connotation. When the welding is completed, because of the dehydrogenation heat treatment, the process of welded joint reheating ( including cooling) is called postheat. When the welding is completed, because of the relaxation of welding residual stress, the process of welded joint reheating (including cooling) is called post-weld heat treatment. According to the above definition and relevant technical connotation, although the high air temperature has certain advantages to welding quality, it cannot substitute preheating, which is because that the preheating temperature is much higher than the air temperature.
6
Embed
Position and function of preheating technology in welding ...
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
· ·112
Position and function of preheating technology in welding application technology
Guanfu Sun 1, Weizhi Dai 1, 2, Wei Zhang 1
(1. Jinggong Steel Building Group, Zhejiang 312030, China; 2. China
Engineering Construction Welding Association, Beijing 100088, China)
Abstract: Combining with the superficial understanding of
preheating in practical engineering application, this paper expounds
the preheating technology starting with its definition. Considering
the current situation of insufficient understanding to preheating,
this paper makes explanation and illustration of relevant point,
introducing the related technical theory in simple terms. At the same
time, this paper also recommends several methods to determine the
preheating temperature, trying to make readers learn more about the
position and function of preheating technology in welding process by
combining with engineering project. t100, one of the most important
parameters, is introduced in this article, which has an important
role on the preventing of hydrogen-induced crack in strength steel
Senior engineer; To be engaged in the development and research and application of steel structure welding application technology, and be good at the formulation of design and welding technology of large-scale complex steel structure system. There is a certain accomplishment in the welding technique of steel structure of construction steel. Strong theoretical foundation and rich practical experience.
Be willing to cooperate with international coun-terparts.