Customization of Steel Template Specifications: What are the Common Types of Defects in Steel Templates?

1、 Inherent defects in materials
Cracks and delamination
There are micro/macro cracks on the surface or inside, which can easily cause stress concentration
Rolling defects in the sheet metal result in interlayer delamination and separation in the thickness direction
Inclusions and pores
Non metallic inclusions (oxides, sulfides) reduce the mechanical properties of materials
During the pouring process, gas retention forms holes with a diameter greater than 2mm, which need to be repaired
Surface oxidation and corrosion
Improper storage leads to thickening of the oxide layer (>50 μ m), which affects the welding quality
Pitting corrosion caused by peeling of galvanized layer, with a corrosion rate greater than 0.1mm/year, needs to be scrapped
2、 Processing and forming defects
Welding defects
Source of Defect Type Characteristics
There is a clear boundary between the unfused weld seam and the base metal interface
Residual welding slag inside the slag inclusion weld (size>1.5mm)
Insufficient melting depth at the edge of the biting base material leads to grooves (depth>0.5mm)
Dimensional deviation
Template length error>± 3mm/m, curvature>L/500
Difficulty in assembly due to bolt hole displacement greater than 1.5mm
Molding defects
Edge wave deformation during roll forming (wave amplitude>2mm/300mm)
Bending angle error>± 1 °, affecting structural assembly accuracy
3、 Construction application defects
Structural defects
Overall collapse caused by instability of the support system (verticality deviation>5mm/m)
The positioning error of embedded parts is greater than 3mm, resulting in subsequent connection failure
Interface defects
Template joint leakage forms honeycomb and rough surface (porosity>5%)
Surface damage of formwork caused by concrete adhesion (peeling depth>0.5mm)
Deformation defect
Localized bulging: buckling deformation in the compressed area (wavelength/amplitude ratio<30:1)
Overall warping: Non uniform deformation caused by temperature difference stress (flatness>5mm/2m)
4、 Special environmental defects
Low-temperature embrittlement
-When working below 20 ℃, the impact toughness decreases by more than 30%
Fatigue damage
Microcracks appear after repeated use for more than 50 times (crack propagation rate>10 ⁻⁶ mm/time)
Key Quality Control Points
Acceptance criteria for defect type detection methods
Weld quality ultrasonic flaw detection defect equivalent diameter ≤φ 2mm
Flatness laser scanner ≤ 2mm/m
Joint gap plug gauge detection ≤ 1.5mm
Surface roughness comparison block method Ra ≤ 12.5 μ m