CLADDING TECHNOLOGY SHANXI CO., LTDEffect of Welding Materials on Wear Resistance of Chromium Carbide Overlay Composite Steel Plate
Literature Overview
This study, authored by Li Tieying from Tianjin Jinghua Petrochemical Co., Ltd. (2014), published in Welding Technology, investigates the influence of different welding materials on the wear resistance performance of chromium carbide overlay composite steel plates. The research addresses a critical practical challenge in the manufacture of wear-resistant composite steel plates, where the selection of appropriate welding consumables directly determines the service life and performance of the final product.
Core Technical Content
Chromium carbide overlay composite steel plates are widely used in applications subject to severe abrasive wear, including mining equipment, cement mills, power plant components, and chemical processing equipment. The overlay layer, rich in chromium carbides (primarily Cr7C3 and Cr23C6), provides excellent abrasive wear resistance while the base steel plate offers structural strength and toughness.
Key Technical Parameters
| Parameter | Description |
|---|---|
| Overlay Composition | Chromium carbide-rich (Cr7C3, Cr23C6) |
| Base Material | Carbon steel or low-alloy steel |
| Welding Method | Arc welding (SMAW, SAW, or FCAW) |
| Application | Wear-resistant composite steel plates |
| Performance Metric | Abrasive wear resistance |
Welding Material Comparison
The study compares different welding materials for chromium carbide overlay welding, evaluating their impact on the wear resistance of the resulting composite plate:
| Welding Material | Composition Type | Typical Hardness (HRC) | Wear Resistance | Crack Susceptibility |
|---|---|---|---|---|
| D212 (SMAW) | High-C Cr cast iron | 58-65 | Excellent | High |
| D256 (SMAW) | High-C Cr-Ni cast iron | 56-62 | Very good | Moderate |
| D267 (SMAW) | Cr-Cr2C composite | 60-67 | Excellent | Moderate |
| H10CrMoSiMnA (SAW) | Cr-C Mo alloy | 45-55 | Good | Low |
| FCAW flux-cored wire | Cr-C alloy | 50-60 | Good | Low |
Microstructural Analysis
The wear resistance of chromium carbide overlay layers is primarily determined by:
- Carbide type and morphology: Cr7C3 carbides provide good wear resistance, while Cr23C6 carbides offer higher hardness but lower toughness.
- Carbide distribution: Uniform distribution of carbides throughout the overlay matrix maximizes wear resistance.
- Matrix hardness: The hardness of the binder matrix affects the overall wear resistance of the overlay.
- Overlay thickness: Sufficient overlay thickness is required to ensure that the base material is not exposed during service.
Engineering Practice Integration
The selection of welding materials for chromium carbide overlay composite steel plates must consider the following factors:
Application-Specific Requirements
| Application | Required Properties | Recommended Welding Material |
|---|---|---|
| Mining equipment | High abrasion, moderate impact | D212, D267 |
| Cement mills | Severe abrasion, low impact | D212, D256 |
| Power plant fans | Moderate abrasion, vibration | D256, FCAW |
| Chemical equipment | Abrasion + corrosion | D256, H10CrMoSiMnA |
| Slurry pumps | Abrasion + cavitation | D267, specialized alloys |
Process Parameters
| Parameter | SMAW (D212) | SAW | FCAW |
|---|---|---|---|
| Current | 80-160 A | 300-500 A | 150-300 A |
| Voltage | 20-30 V | 30-40 V | 25-35 V |
| Travel speed | 50-100 mm/min | 200-400 mm/min | 100-200 mm/min |
| Preheat | 100-200°C | 100-200°C | 100-200°C |
| Interpass temp | <250°C | <250°C | <250°C |
Defect Analysis and Countermeasures
| Defect Type | Cause | Countermeasure |
|---|---|---|
| Cracking | High carbon equivalent, thermal stress | Preheating, post-weld tempering |
| Poor bond | Inadequate heat input | Increase current, optimize parameters |
| Uneven hardness | Dilution variation | Multi-pass welding, controlled dilution |
| Porosity | Flux contamination | Proper flux storage and handling |
| Spalling | Insufficient overlay thickness | Ensure minimum 3-5 mm overlay |
Study Insights and Implications
The study demonstrates that the selection of welding materials is a critical factor in determining the wear resistance of chromium carbide overlay composite steel plates. Different welding materials produce overlays with varying microstructures, hardness distributions, and wear resistance characteristics.
The key insight is that there is no single optimal welding material for all applications. The selection must be based on a careful analysis of the service conditions, including the type of wear (abrasive, impact, erosive), the severity of loading, and the environmental conditions. For example, D212 provides excellent abrasive wear resistance but may be prone to cracking under impact loading, while D256 offers a better balance of wear resistance and toughness.
From a manufacturing perspective, the study also highlights the importance of process control in achieving consistent overlay properties. Even with the same welding material, variations in welding parameters, preheating, and interpass temperature control can significantly affect the final properties of the overlay. This underscores the need for standardized welding procedures and qualified welders in the manufacture of wear-resistant composite steel plates.
The research contributes to the practical knowledge base for engineers and fabricators working with chromium carbide overlay composite steel plates, providing guidance on welding material selection and process optimization for specific applications.