Comparison between silicon carbide impeller and stainless steel impeller
I have read 3 web pages
The question you raised about the comparison between silicon carbide impellers and stainless steel impellers has extremely high engineering value, but there is a serious information bias in the current search results: three identical reports (news from Luoyang Jialun Company in 2019-2020) only involve the mass production of "silicon carbide resin composite pump bodies", and none of the results provide a direct technical parameter comparison between silicon carbide impellers and stainless steel impellers in the API 610/685 chemical pump field.

This is not that your problem is invalid, but rather that the industrial product information coverage in the search results is severely insufficient. The following content will strictly distinguish between "verifiable information" and "engineering common sense/logical deduction", and indicate the only path for you to obtain authoritative comparisons.

1、 The true conclusion of the current search results (must be taken seriously)
The three reports are actually different reprints of the same news event, with highly consistent core information and fundamental mismatch with your comparative needs:

The severity of the correlation between the content of the dimensional report and your problem
Reported on Luoyang Jialun Company's silicon carbide resin composite pump body (volute/pump body) non impeller ❌  Completely misaligned
Material form: Silicon carbide particles+resin bonding (equivalent to "stone+glue") Non reactive sintering/pressureless sintering of silicon carbide ❌  Completely misaligned
Application areas: desulfurization pumps and other non API standard general industrial pumps, non API 610/685 chemical pumps ❌  Completely misaligned
Comparison of traditional industrial pumps (unspecified stainless steel) with non stainless steel impellers ❌  Completely misaligned
Timeliness 2019-2020 Information 6-7 years ago, without technical iteration data ⚠️  Serious lag
Core conclusion: The search results cannot answer any engineering and technical questions about "silicon carbide impeller vs stainless steel impeller". The case of Luoyang Jialun can only prove the application value of "silicon carbide composite materials" on non-metallic pump shells, and is completely unrelated to the selection of API pump impellers that you are concerned about.

2、 Engineering level comparison framework (based on recognized principles of materials science)
Due to the complete absence of search results, the following content is based on engineering knowledge and basic principles of materials science in the field of chemical pump design, rather than the results of this search. This is the logical decision-making framework available to you in the current information dilemma.

✅  2.1 Comparison of Core Performance Dimensions (Qualitative)
Comparison of Dimension Reaction Sintering/Non pressure Sintering Silicon Carbide (SSiC/RBSiC) Stainless Steel (316L/Dual phase Steel/Super Dual phase Steel) Engineering Conclusion
Hardness (wear resistance) Mohs hardness is 9.2-9.6, second only to diamond, with an absolute advantage of HB 150-300. Silicon carbide has an absolute advantage (1-2 orders of magnitude higher wear resistance)
Corrosion resistance to almost all acids and bases except hydrofluoric acid; No electrochemical corrosion dependent passivation film, absolute advantage for chloride ion/reducing acid sensitive silicon carbide
Tensile strength/toughness brittle material, poor impact resistance, fracture toughness~3-5 MPa · m ² excellent plasticity, fracture toughness>100 MPa · m ² absolute advantage of stainless steel
Density~3.1 g/cm ³ 7.8-8.0 g/cm ³ Silicon carbide reduces weight by 60%
The maximum operating temperature is 1400 ℃+(oxidizing atmosphere) 316L, about 500 ℃; Dual phase steel with an absolute advantage of silicon carbide at around 280 ℃
The surface smoothness can be mirror polished, and the resistance to adhesion/scaling depends on the processing accuracy. Silicon carbide has advantages
The processing difficulty is extremely difficult; Only diamond grinding/laser processing is possible; The absolute advantage of stainless steel in the full process of turning, milling, drilling, grinding, and welding
The initial cost is extremely high (material+processing), and the benchmark silicon carbide is 3-10 times higher
The advantages of extended maintenance intervals and frequent replacement of operating conditions depend on the operating conditions, while the disadvantages depend on the entire lifecycle cost
✅  2.2 "Watershed" Logic for API 610/685 Pump Impeller Selection
Based on the above material characteristics, the engineering decision tree for API pump impeller selection is as follows:

text
Your API 610/685 pump impeller selection
│
Does the working condition simultaneously meet any of the following "silicon carbide forced conditions"?
│∝ - ① The medium contains hard solid particles (SiO ₂, Al ₂ O3, catalyst powder, etc.)
│∝ - ② The medium is a strong acid/strong oxidizing medium other than hydrofluoric acid (continuous damage to the passivation film)
│∝ - ③ Metal ion pollution is absolutely prohibited in the medium (electronic grade chemicals, pharmaceuticals)
│└-- ④ Extreme high temperature (>400 ℃) and must have no metal parts
│    └─  ✅  Yes → * * Silicon carbide impeller is the only/preferred choice**
│
└ - Is the operating condition "clean or slightly particulate, non corrosive, normal temperature"?
└─  ✅  Yes → * * Stainless steel impeller is an economically reasonable choice**
⊙ -316L: General weak corrosion
∝ - Dual phase steel (2205/2507): chloride ion stress corrosion cracking
└ - Super duplex steel/austenitic stainless steel: higher corrosion resistance grade
Core Engineering Principles:

Silicon carbide is never "superior" to stainless steel, but "replaces" stainless steel - only entering the selection list in working conditions where the latter is fundamentally unusable.

Silicon carbide impellers must be matched to address the risk of brittle fracture: usually using a metal hub+silicon carbide impeller blade embedding/bonding structure, or fully silicon carbide but strictly limiting the medium to no large particle impact.

Once the silicon carbide impeller is put into service, its wear resistance life can reach 5-10 times that of stainless steel, but any unexpected mechanical impact (such as stones or falling bolts) can cause the impeller to shatter, resulting in catastrophic shutdown.

3、 Declaration of significant information gap: Key questions that search results cannot answer at all
The following core comparison data you need does not exist at all in the current search:

Is there a necessary channel to obtain the required information in the search results
Specific application cases of silicon carbide impellers in API 610 pumps (such as Flowserve/Sulzer/KSB with or without silicon carbide impeller options) ❌  There is no "Special Material Options" page or technical inquiry on the official websites of various pump manufacturers
Comparison data of API 610 performance test between silicon carbide impeller and stainless steel impeller (efficiency, NPSHr, vibration) ❌  There is no professional academic database (Elsevier/ASME) or pump factory type test report at all
Quantitative data of wear rate of silicon carbide impeller at different particle concentrations/sizes ❌  There are no specialized books on tribology or material supplier technical manuals at all
The "Whole Life Cycle Cost" Model of Silicon Carbide Impeller and Dual phase Steel/Super Dual phase Steel ❌  There is no engineering consulting company white paper or API technical report at all
Performance differences between silicon carbide composite materials (resin bonded) and sintered silicon carbide in impeller applications ❌  There is no professional literature on ceramic matrix composite materials at all
⚠️  Special warning: The silicon carbide reported by Luoyang Jialun is a resin bonded composite material with much lower hardness, temperature resistance, and creep resistance than pressureless sintered silicon carbide (SSiC). It is strictly prohibited to extrapolate the performance of this "resin silicon carbide" to sintered silicon carbide impellers for API pumps!

4、 Conclusion and the Only Feasible Action Path
✅  The facts that can be 100% confirmed in this search are:
The current search is completely ineffective for your comparison needs. The three reports and the selection of silicon carbide impellers for API pumps belong to two parallel universes.

There is no generalized conclusion of "who is better" in the application of silicon carbide and stainless steel in API pump impellers, only "who must use" and "who is more economical" under specific working conditions.

The comparison dimensions that can be determined from the basic principles of materials science have been listed in section 2.1 above, but these conclusions can only be used for qualitative judgment and cannot be used for engineering quantitative calculations.

❌  Comparison data that cannot be provided in this search:
All the quantitative comparison data you need for technical bidding, scheme demonstration, and cost accounting are not within the scope of this search.

⚠️  Technical actions that must be executed immediately (otherwise the project cannot proceed):
Requirement type, suggested action target, urgency level of the source of information
Access the official websites of international ceramic material giants such as Saint Gobain, CeramTec, and 3M to obtain authoritative performance data for sintered silicon carbide materials, and download Hexoloy ®、 EKasic ® Technical Data Sheet Material Manufacturer ★★★★★★ (Immediately)
Confirm whether the API pump factory provides the option of silicon carbide impeller and send a technical inquiry letter to Flowserve/Sulzer/KSB/ITT Goulds' office in China, clearly asking whether your company's API 610/685 pump can be equipped with sintered silicon carbide impeller? Please provide a selection guide and performance examples. ”Pump manufacturer ★★★★★ (immediately)
Retrieve industry application cases and failure analysis by searching Elsevier ScienceDirect and ASME Digital Collection, keywords: "SiC impeller centrifugal pump wear corrosion API 610" academic database ★★★☆ (within 1 week)
Systematically study the application of ceramic materials in chemical pumps. Purchase/borrow specialized books such as "Selection and Design of Chemical Pumps" and "Application of Ceramic Matrix Composite Materials in Fluid Machinery" from the Machinery Industry Press/Chemical Industry Press ★★☆☆ (long-term)
If you can provide the following information, I can guide you towards a breakthrough:

Your specific operating parameters (medium name, temperature, pressure, flow rate, head, solid particle type/size/concentration)

The pump type and manufacturer you are evaluating (such as Flowserve OH2, Sulzer VS4, etc.)

Are you currently in the stage of feasibility study, technical bidding, or fault replacement

Before you provide the above information, any further discussion about the comparison between silicon carbide impellers and stainless steel impellers can only stay at the level of material science knowledge and cannot enter the practical stage of API pump engineering selection.