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Volume 34 Number 6 December 2008 Baosteel Technology
Science & Technology of BaotouSteel (Group) Corporation Vol.34, No.6December, 2008
Method and application of flame correction deformation
Lu Yonghe 1, Chen Jingang 2
(1 Baotou Steel Rare Earth Co., Ltd., Baotou 014010, Inner Mongolia;
2 Inner Mongolia Baotou Iron and Steel Co., Ltd. Coking Plant, Baotou 014010, Inner Mongolia)
Abstract: This article discusses how to use various methods to prevent and reduce welding deformation and stress according to the deformation law of welded members, correctly use flame correction methods to correct its deformation, and the heating position heating method, heating temperature and correction during flame correction. Steps, etc. Keywords: stress; thermal expansion and contraction; deformation law; process method; correction ability; effect
Chinese picture classification number: TG44 Document identification code: B Article number: 1009-5438 (2008) 06-0021-03
(1.RareEarthCo. Ltd. ofBaotouSteel (Group) Corp., Baotou014010, NeiMonggol, China;
2.CokingPlantofSteelUnionCo. Ltd. ofBaotouSteel (Group) Corp., Baotou014010, NeiMonggol, China)
Abstract: Accordingtothedeformationallawofweldmember, thepaperdiscussestakingallkindsofmethodstopreventandreducethedeformationandthestress, correctlyusingflamemethodtocorrectthedeformation, andtheheatposition, way, temperature-stepandincorrecting.
Keywords: stress; expansioncausedbyheatandcontractionbycold; deformationlaw; technicalmethod; correctioncapacity; effect
Steel is affected by high temperature and its chemical composition remains unchanged, but its mechanical properties have changed greatly. The heating and cooling of welding is a special heat treatment. Due to the uneven heating of the workpiece and the cooling shrinkage of the weld, deformation and internal stress after welding are unavoidable, but in order to obtain high-quality welded joints and reduce welding stress and deformation, we can prevent and reduce as long as we master the law Welding deformation and stress.
The shrinkage caused various deformations of the welded structure. Since the uneven heating of the welding will cause deformation of the workpiece, under certain conditions, we can also use the uneven heating method to cause new deformation to correct the welding deformation that has occurred. This new deformation is used to offset welding deformation and achieve the purpose of correcting welding deformation. Different heating positions can correct deformation in different directions, and different heating temperatures can obtain different ability to correct deformation. In general, the heating position is selected properly. The higher the heating temperature, the stronger the correction ability, and the larger the correction distortion.
1 Principle of flame correction deformation
Local uneven heating of the weldment during welding is the cause of welding deformation and stress. After welding, the metal in the weld and the heated area near the weld is cooled and shortened. The shortening is mainly manifested in two directions, namely longitudinal shrinkage along the length of the weld and transverse shrinkage perpendicular to the length of the weld. Because of these two directions
2 Preparations before flame correction
2.1 Detection of deformation
Before and during the flame correction, the deformed parts and the degree of deformation of the structure must be inspected to determine the heating position.