Product Overview
High-chromium cast iron pump parts refer to all pump wear parts that are manufactured from high-chromium white cast iron via the casting process; they encompass all wetted parts, such as impellers, pump casings, front/back liners, volute liners, and wear rings.
Thanks to its exceptional resistance to abrasion, abrasive‑particle wear and erosion, high-chromium cast iron is the preferred material for pump wear parts of slurry pumps, mortar pumps, mud pumps, and mining centrifugal pumps, which directly contact high concentrations of solid particles.
Customizable Specifications
| Item | Customizable Specifications |
| Product Name | High-Chromium Cast Iron Pump Parts / High-Cr Cast Iron Pump Parts |
| High-Chromium Grades | A05 (Cr26~27%), A07 (Cr15Mo3), BTMCr26 / BTMCr27, customized Cr/Mo alloy on request |
| Hardness After Heat Treatment | A05: HRC 58–62; A07: HRC 60–64 |
| Single Part Weight | 3kg – 2,000 kg |
| Casting Processes | Green Sand Casting, Resin Sand Casting, Lost Foam Casting |
| Abrasion Resistance | For pumps processing high-hardness particle medium, the abrasion resistance is much better than high Mn steel pump castings |
| Working Medium | Slurry SG≤1.8, solid content ≤45%, particle size 0.5–50mm, pH 5–12 |
| Continuous Medium Temperature | -20℃ - 120°C |
| Max Passing Solid Particle | 60mm |
| Surface Treatment | Shot blasting, anti-rust oil, anti-corrosion primer coating |
| MOQ | 200kg |
| Certification | ISO 9001, ISO 14001, ISO 45001 |
Advantages of High-Cr Cast Iron for Pump Parts
High-chromium cast iron has high chromium content and sufficient carbon content, enabling pump castings to form M₇C₃-type chromium carbides with hardness up to HV 1500–1800, and the surface hardness can reach HRC 58–65.
Consequently, high-chromium cast iron pump parts can effectively withstand erosion by hard particles under longer time operation.
When the chromium in high-chromium cast iron comes into contact with acidic or alkaline media, a Cr₂O₃ passivation film rapidly forms on the component's surface, protecting it from further corrosion or dissolution.
If the passivation film is damaged by the scraping action of hard particles, the high-chromium cast iron pump components will regenerate the film, continuing to protect against corrosion.
Is your pump suffering from reduced flow or head, increased vibration and noise, or medium leakage caused by excessive wear? Are frequent inspections and part replacements required due to these issues?
If so, high-chromium cast iron pump parts will be of great help to you. Their service life is several times longer than that of ordinary cast iron pump components, supporting your efficient and smooth pumping operations.
Available Material Grades
We manufacture custom high-chromium cast iron pump parts based on materials specified in customer drawings.
Alternatively, our engineers can select the appropriate grade from the ASTM A532 standard based on operating conditions of your pumps - such as abrasion, impact, and corrosion level of medium.
Key materials include:
A07 / ASTM A532 Class IIB / Cr15Mo3
This grade offers excellent toughness and resists chipping, spalling, and cracking under impact from large particles;
Its superior hardenability ensures uniform wear resistance throughout thick-walled high-chromium cast iron pump parts (t≥40mm) and reduces the risk of internal cracking.
A05 / ASTM A532 Class IIIA / Cr26 / Cr27
A05 high-chromium cast iron pump parts resist rapid wear and wall-thinning caused by hard particle erosion, deliver an extended service life under high-hardness-medium working conditions such as mining, mineral processing, and dredging.
The A05 material offers a more competitive unit price than that of A49, providing superior cost-effectiveness.
A49 / ASTM A532 Class IIIB / Cr30
Under service conditions with both abrasion and mild‑acid corrosion such as FGD gypsum slurry, A05 or A07 will suffer rapid corrosion and premature failure. In such cases, A49 shall be the preferred material.
It forms a passivation film to inhibit acid attack on pump components and reduce large‑scale carbide spalling, extending service life.
However, A49 cannot be used in strongly acidic media at pH < 3.5.
Precision Machining of High-Chromium Cast Iron Pump Parts
High-chromium cast iron castings for pumps are extremely difficult to machine due to their high hardness and material brittleness; even the slightest mishandling can lead to issues such as edge chipping, notches, micro-cracks, post-machining deformation, and failure to meet roughness or dimensional accuracy standards, ultimately resulting in the castings being scrapped.
To ensure the high-efficiency and high-quality machining of high-chromium cast iron pump components, we adopt targeted measures across five key areas:
PCBN (polycrystalline cubic boron nitride) tools are necessary for machining high-chromium cast iron pump parts.
They possess a hardness of HV 3000–4500, and do not suffer a loss of hardness due to high cutting temperatures, so they can prevent rapid wear and edge chipping while ensuring a smooth surface finish and high precision of the pump castings.
Large cutting‑depth parameters shall not be set to shorten machining time, otherwise, heat and impact generated by high‑speed, high‑load cutting will cause micro‑cracks, and finally cause cracking of high-chromium cast iron pump castings in service.
The machining process must adopt shallow cutting depth, medium-to-high cutting speeds, and a moderate feed rate to strictly control heat generation and prevent thermal stress cracking.
Additionally, the tool entry angle and cutting path should be carefully designed to avoid impact-induced cracking caused by interrupted cutting.
Poor fixture design can cause part deformation, compromise the dimensional accuracy of pump castings, and potentially lead to surface damage or cracking.
During design, the clamping force of the hydraulic chuck should be minimized while still ensuring no slippage occurs; copper pads should be used to protect critical contact surfaces and prevent surface damage.
The machining process of high-chromium cast iron pump parts should be carried out in two steps: rough machining + finish machining.
After rough machining, unclamp the pump castings to relieve elastic and machining stresses, followed by finish machining.
Add small chamfers to structures such as sharp corners, flange edges, threaded hole openings, and sealing steps to eliminate sharp edges, which are prone to stress concentration and chipping.
Hot Tags: high-chromium cast iron pump parts, China high-chromium cast iron pump parts manufacturers, suppliers, factory
