LDS-50KN Universal Tensile Testing Machine for Galvanized Steel Sheets

Overview

The LDS-50KN Universal Tensile Testing Machine is an electromechanical static testing system engineered for precise mechanical characterization of galvanized steel sheets and related metallic sheet materials. It operates on the principle of uniaxial tensile loading under controlled displacement rate, conforming to the fundamental test methodology defined in GB/T 228.1–2022 (equivalent to ISO 6892-1:2019 and ASTM E8/E8M). The machine integrates a high-stiffness dual-column load frame, a digitally regulated PWM servo-motor drive, and a microprocessor-based closed-loop control architecture to ensure consistent force application and displacement tracking across the full operational range. Its design emphasizes repeatability and traceability in industrial quality control environments—particularly for incoming material verification, in-process lot release, and post-galvanizing mechanical property validation.

Key Features

• Robust dual-column structural frame with precision-ground guide rails and preloaded ball screws, minimizing lateral deflection during high-load testing (up to 50 kN).
• High-stability load cell calibrated to ±1% full-scale accuracy, featuring temperature-compensated strain gauge technology and 0.01 N force resolution for sensitive yield point detection.
• Digitally controlled crosshead speed regulation via PWM-driven AC servo motor, delivering stable test velocities from 10 mm/min to 500 mm/min with ±1% speed accuracy across the entire range.
• Dedicated fixture set optimized for galvanized sheet specimens—including pneumatic or manual wedge-action grips with serrated hardened steel jaws to prevent slippage and edge damage during clamping.
• Integrated embedded controller with real-time display of load, displacement, strain (via optional extensometer input), and calculated engineering stress–strain curves.
• Onboard thermal printer for immediate hard-copy output of test reports including peak load, yield strength (Rp0.2), ultimate tensile strength (Rm), elongation at break (A50), and modulus of elasticity (E).

Sample Compatibility & Compliance

The LDS-50KN accommodates standard flat-sheet tensile specimens per GB/T 228.1–2022 Annex B (e.g., Type P1, P2, or non-proportional flat specimens with widths of 12.5 mm, 20 mm, or 25 mm). Specimen thickness range supports typical hot-dip galvanized steel products (0.3–3.0 mm). All measurement functions are traceable to national metrological standards; load cell calibration certificates are provided with each unit. The system meets essential requirements of ISO/IEC 17025 for testing laboratories and supports audit-ready documentation for internal QC, third-party certification (e.g., ISO 9001), and supplier qualification programs. While not FDA 21 CFR Part 11–compliant out-of-the-box, raw data export (CSV/Excel) enables integration into validated LIMS or ELN platforms for regulated environments.

Software & Data Management

The embedded firmware provides real-time curve plotting, automatic yield point identification (0.2% offset method), and standardized report generation. Data can be exported via USB port in CSV format for post-processing in MATLAB, Excel, or statistical analysis tools (e.g., Minitab). Optional PC-based software (sold separately) adds advanced features: multi-curve overlay, batch test sequencing, user-defined pass/fail criteria, electronic signature support, and GLP-compliant audit trail logging. All digital outputs retain timestamp, operator ID, specimen ID, environmental conditions (manually entered), and calibration status metadata.

Applications

• Verification of mechanical compliance for cold-rolled galvanized steel coils prior to stamping or forming operations.
• Quality assurance of galvanized sheet batches in automotive body-in-white (BIW) supply chains.
• Comparative evaluation of zinc coating adhesion effects on tensile ductility and necking behavior.
• Process validation of continuous galvanizing line (CGL) parameters—e.g., annealing temperature, cooling rate, and zinc bath chemistry—via correlation with Rm and A80 values.
• Supporting root-cause analysis of premature fracture in finished stamped parts through retrospective mechanical property trending.

FAQ

Does this machine comply with international tensile testing standards beyond GB/T 228.1?
Yes—it implements core test methodologies aligned with ISO 6892-1:2019 and ASTM E8/E8M, though formal certification to those standards requires third-party verification and documented calibration against accredited reference standards.
Can the system accommodate extensometers for true strain measurement?
The controller includes analog inputs compatible with clip-on or non-contact video extensometers (optional accessories); strain data can be synchronized with load and displacement for true stress–strain analysis.
Is the thermal printer capable of generating compliant QA records for ISO 9001 audits?
Yes—printed reports include unique test ID, date/time stamp, operator name, equipment ID, calibration due date, and measured parameters; users must maintain associated calibration logs and environmental records separately per ISO 9001 clause 7.1.5.
What maintenance intervals are recommended for long-term accuracy retention?
Load cell recalibration is advised annually or after 10,000 test cycles; mechanical inspection (lubrication, screw preload, grip wear) is recommended every 6 months under continuous operation.
Are custom夹具 (fixtures) available for non-standard specimen geometries?
Yes—custom-designed grips, shear fixtures, or peel test adapters can be supplied upon request, subject to mechanical feasibility review and lead-time confirmation.