Quality Control
Centered around the physical and chemical laboratory, we have established a "full-process, full-dimension, full-traceability" quality control system. From raw material intake to finished product dispatch, every process step strictly complies with international standards, ensuring that we provide customers with reliable, high-quality casting products.
Physical and Chemical Laboratory
The "Microscope" and "Weights and Measures" of Quality
Laboratory Positioning
Changlong Machinery’s standardized physical and chemical laboratory is a professional testing facility integrating composition analysis, performance testing, and process verification. The laboratory features a dedicated independent zone, equipped with a constant temperature and humidity environment as well as a professional ventilation system, ensuring precise test data and safe experimental operations. It serves as the core hub for safeguarding product quality throughout the entire process, from raw materials to finished products.
Core Testing Capabilities
Coordinate Measuring Machine（CMM）
Tool Presetter / Off-line Tool Setting Gauge
Metallographic microscope
Brinell Hardness Tester
Full-process quality control workflow
Full-chain control
01
Source Control
Incoming Material Inspection
• Control scope: All incoming materials including pig iron, scrap steel, alloy auxiliary materials, mold materials, etc.
• Control actions:
√ Verify supplier qualifications and material certificates, and establish a "List of Approved Suppliers";
√ Carry out sampling and submit samples to the physical and chemical laboratory for three‑fold testing (composition, appearance, and dimensions);
√ Only materials that pass inspection are accepted into inventory. Non‑conforming items shall be isolated and returned, preventing substandard raw materials from entering production.
02
Process Interception
In-Process Inspection
• Key control points: Bonding, dip coating, melting, molding, pouring, machining and other critical processes.
• Control actions:
√ Melting process: Real‑time monitoring of molten iron temperature and composition; spectrometric analysis of furnace samples; pouring is allowed only after passing inspection.
√ Molding/pouring process: First‑article inspection to confirm mold and pouring parameters; Checks during patrol inspections to promptly identify risks such as porosity and slag inclusion.
√Machining process: Key dimensions are measured using CMM; implement a three‑level inspection system of "self‑inspection + peer‑inspection + special inspection" to ensure machining accuracy meets requirements.
03
Outgoing Quality Control
Final Inspection of Finished Products
Control scope: All finished castings that have undergone complete processing and cleaning.
• Control actions:
√Re-inspection by the physical and chemical laboratory: Perform spot checks on finished products for composition, metallography, and mechanical properties; retain test reports.
√Full dimensional inspection: Measure all critical dimensions using CMM; verify against drawing tolerance requirements.
√Visual inspection: Manual + vision‑assisted inspection to identify surface defects such as cracks, burrs, and rust.
√Outgoing inspection – Delivery commitment:
Before finished products are dispatched, re‑verify product model, quantity, and packaging; check that packaging protection is adequate to prevent wrong shipments, missing items, or damage.
Quality Assurance System
The Core Pillar of Continuous Improvement
Technical Cooperation for Empowerment
The laboratory has engaged in in-depth industry‑university‑research collaboration with institutions such as Zhejiang University City College, jointly carrying out casting process optimization and new material development. These efforts continuously enhance lost foam casting and precision machining capabilities, strengthening the quality foundation through technological innovation.
Standardization and Compliance
√Follow the quality management system; prepare standardized documents such as Casting Process Procedures and Finished Product Inspection Specifications to ensure every process step is well‑defined and traceable.
√Strictly implement environmental compliance requirements, simultaneously achieving both quality and environmental standards to build a green, compliant, and high‑quality production system.
Data‑Driven Management
Establish a quality data dashboard to monitor core indicators in real time, including incoming material pass rate, process defect rate, and first‑time pass rate of finished products, facilitating efficient management.
Core Commitment
Based on precise testing, ensured by full-process control, and supported by technological innovation, we provide global customers with high-quality, high‑reliability casting products and customized manufacturing services.
