| Base Plate Material | Low-carbon or mild steel plate is commonly used as the structural backing. | Typical carbon steel backing thickness: approximately 3–25 mm, depending on application. | Provides load-bearing strength, weldability, and support for the wear-resistant overlay. |
| Overlay Alloy System | Iron-based weld metal containing chromium carbides, with carbon and chromium as the principal alloying elements. | Chromium content is often about 15–35%; carbon is commonly about 2–6%, depending on formulation. | Controls carbide formation, abrasion resistance, crack pattern, and weld-metal toughness. |
| Surface Preparation | The backing plate is cleaned by removing oil, rust, moisture, scale, and loose contaminants before welding. | A clean, dry, metallic surface is required in the weld zone. | Reduces porosity, lack of fusion, inclusions, and premature delamination. |
| Overlay Deposition Process | Open-arc, submerged-arc, flux-cored arc, or other controlled welding processes may be used according to plate design. | The process is selected for deposition rate, plate size, alloy chemistry, and required surface profile. | Determines productivity, dilution, bead quality, heat input, and consistency across the plate. |
| Preheating and Interpass Control | Temperature is controlled to limit thermal shock and manage hydrogen-related cracking in the backing steel. | The required temperature depends on base-steel chemistry, thickness, restraint, and welding consumables. | Supports weld integrity and helps control distortion and cracking. |
| Overlay Thickness | One or more weld layers are deposited to achieve the required wear allowance. | Common finished overlay thickness: approximately 3–15 mm; heavier designs may exceed this range. | Greater thickness generally provides more wear allowance, but may increase weight and residual stress. |
| Carbide Microstructure | Primary chromium-rich carbides form within an iron-based eutectic matrix during solidification. | Typical carbide volume fraction is approximately 20–40%, depending on alloy and deposition parameters. | Carbide size, distribution, orientation, and matrix chemistry strongly affect abrasive wear performance. |
| Hardness Measurement | Hardness is tested on the overlay surface using a suitable standardized method. | Typical overlay hardness is about 55–65 HRC, or approximately 600–800 HV, subject to alloy and test location. | Confirms whether the deposited layer meets the specified resistance to abrasive wear. |
| Surface Crack Pattern | Fine transverse stress-relief cracks may appear in chromium carbide overlay weld metal. | Crack spacing commonly falls in the range of roughly ger 20–100 mm, but it varies with alloy, thickness, and heat input. | Controlled surface checking can relieve welding stress; unacceptable cracks or cracks reaching the backing plate require evaluation. |
| Dimensional Tolerance | Plates are inspected for length, width, total thickness, flatness, and overlay uniformity. | Tolerance is normally agreed in the purchase specification; cutting and forming allowances must be defined before production. | Ensures the plate can be fitted, formed, welded, or bolted into the intended equipment. |
| Cutting and Fabrication | Plates may be cut using plasma, abrasive, or other suitable methods; cutting is normally performed from the backing side when practical. | Machining of the hard overlay is limited; grinding or specialized cutting tools may be required. | Correct fabrication methods protect the overlay and reduce heat-affected damage. |
| Quality Inspection | Inspection may include visual examination, dimensional checks, hardness testing, chemical analysis, and ultrasonic or other nondestructive testing when specified. | Inspection scope should be agreed before order placement and recorded on the inspection certificate. | Verifies overlay continuity, bonding quality, chemistry, dimensions, and traceability. |
| Typical Applications | Mining, cement, steel, power generation, aggregate processing, recycling, and bulk-material handling equipment. | Suitable for sliding, gouging, or low-to-moderate impact abrasion; severe impact may require a different alloy system. | Application conditions determine whether chromium carbide overlay is the appropriate wear solution. |
| Selection Criteria for 2026 Purchasing | Evaluate alloy chemistry, overlay thickness, backing grade, production process, inspection capability, fabrication support, and delivery capacity. | Use application-specific requirements rather than hardness alone when comparing manufacturers. | A balanced specification improves service life, installation reliability, and total operating cost. |
