Steel template manufacturers supply for rent: How to deal with steel template size accuracy that is not up to standard? 双语对照 笔记

1、 Defect classification processing
1. Defects related to welds
Misalignment of weld seam: Use an angle grinder to polish the misaligned area, and retest after welding (the welding current should be 10% -15% lower than the original welding parameters)
Weld shrinkage deformation: Linear flame correction (heating temperature 650 ± 50 ℃, bandwidth 20mm) is used, and mechanical bending force is synchronously applied
2. Structural deviation
Axis displacement exceeds the standard:
Loosen the connecting bolts and recalibrate with a laser locator. If the deviation is greater than 5mm, it needs to be cut and re welded
Add limit clamps and add 2 positioning barriers per linear meter
Diagonal error:
When the diagonal difference is greater than 3mm/m, use a hydraulic extension device to apply diagonal pressure correction (single correction amount ≤ 2mm)
Defects caused by equipment deviation need to be adjusted for the axis deviation of the hoist, and the compensation amount should be gradually corrected at 0.3mm/time
3. Surface defects
Local indentation: Fill with epoxy resin for depths ≤ 2mm, and weld and polish for depths ＞ 2mm (surface roughness Ra ≤ 6.3 μ m)
Wave deformation: When the wavelength is greater than 300mm, multi roll mechanical correction is used, and when the wavelength is less than 300mm, triangular heating method is used for treatment
2、 Repair process
Preprocessing evaluation
Measure the deviation three-dimensional coordinates using a total station and generate a deviation chromatogram (marked in red outside the tolerance zone)
Perform hardness testing on the defective area (HB difference>30 requires annealing treatment)
Correction process selection
Defect type correction method accuracy restoration standard
Flatness exceeding tolerance hydraulic leveling machine+laser positioning ≤ 1.5mm/m
Hole deviation, hole expansion+liner compensation (liner wall thickness ≥ 2mm), concentricity ≤ 0.5mm
Insufficient cross-sectional size, welding reinforcement plate (overlap length ≥ 50mm), thickness tolerance ± 1mm
Post processing validation
Pre load test within 24 hours after repair (load value is 120% of the design value)
Ultrasonic thickness gauge is used to perform flaw detection on the repaired welding area (defect echo ≤ φ 2mm flat bottom hole equivalent)
3、 Prevention and control system
Process improvement
Before template assembly, a "three inspection system" is implemented: self inspection (by the operator), mutual inspection (by the team), and specialized inspection (by the quality inspector)
The welding process follows the WPS specification, and the interlayer temperature is controlled between 80-150 ℃
Equipment management
Regularly calibrate the parallelism of the straightening machine rollers (tolerance ≤ 0.05mm/m)
Cutting equipment undergoes monthly dynamic accuracy testing (repeated positioning accuracy ≤ ± 0.1mm)
Standardized control
Establish a size deviation database and implement SPC process control (CPK ≥ 1.33)
Carry out acceptance according to GB50205 standard:
Plane position deviation ≤ ± 3mm, verticality ≤ 2mm/m
Concentricity error of bolt holes ≤ 1mm, gap between joints ≤ 1.5mm
Through the above processing system, the qualified rate of repairing unqualified steel formwork can reach over 95%, and the recurrence rate of similar problems can be reduced to below 3%.