High-Temperature Materials for Industrial Applications

MATECH Ultra-High-Temperature (UHT) Oxide Fibers for CMCs.   MATECH has developed the world’s first ultra-high-temperature (UHT) oxide structural ceramic fiber, known as Refractory-Alloyed Yttrium Aluminum Garnet (RAYAG). With this innovation, oxide/oxide (Ox/Ox) ceramic matrix composites (CMCs) can challenge the decades long dominance of non-oxide CMCs in high temperature (HT) and UHT applications. MATECH’s breakthrough enables Ox/Ox CMCs to compete in the demanding applications of high temperature turbines for commercial and military propulsion, non-ablative heat shields, and hypersonic aeroshells. MATECH’s new oxide fiber retains significant strength up to 1600C!   Perhaps the most recognized state-of-the-art (SOTA) oxide fibers commercially available are the Nextel family of oxide ceramic fibers, manufactured by 3M corporation for over 30 years. These sol-gel derived ceramic fibers have allowed Ox/Ox CMCs to perform numerous moderately high temperature roles. Unfortunately, oxide CMCs haven’t been able to compete with the higher temperature capabilities of non-oxide CMCs, such as C/C, C/SiC, and SiC/SiC, as prime examples. They do have, however, long-term stability in oxidizing environments. For the first time, due to this unprecedented innovation, almost indefinite stability at extremely high temperatures can now be achieved in one composite system, RAYAG/RAYAG CMCs.   MATECH developed high ceramic yield dry spinning chemistries to fabricate high yttrium aluminum garnet (YAG) and Refractory Alloyed YAG (RAYAG) structural ceramic fibers and matrices. Refractory Alloyed YAG contains a significant fraction of an ultra-high-temperature refractory metal oxide in a YAG matrix. Dense fibers of both compositions have been demonstrated (Figure 1). Significant high strength retention is observed in RAYAG when compared to state-of-the-art commercial oxide ceramic fibers (see Figure 2). Because they are oxides, unlike SiC fibers, they are not nearly as susceptible to moisture and oxidation-related degradation.  Polymers for YAG and RAYAG matrices have also been developed, thereby eliminating any coefficient of thermal expansion (CTE) mismatch between fibers and matrices in Ox/Ox CMC manufacturing.    Photoluminescence and Thermoluminescence in these systems have been observed when doped with various lanthanide elements, see Figure 2 below for europium-doped YAG fibers. Thermoluminescence would dissipate heat generated during hypersonic flight for TPS and leading-edge applications.   MATECH’s development of RAYAG ceramic fibers and RAYAG/RAYAG CMCs can usher in a new era of ultra-high-temperature oxide CMCs that are sorely needed for such demanding applications as high temperature turbines for commercial and military propulsion, non-ablative heat shields, and hypersonic aeroshells.

Heat-Proof Innovation: New Copper-Tantalum Alloy Withstands 1,472°F and Could Revolutionize Aerospace Design Rethinking the Limits of Heat Resistance in Advanced Engineering Modern aerospace, military, and energy systems demand materials that can endure extreme temperatures and pressures. Traditional nickel-based superalloys have long been the standard, operating close to their melting points to perform under these punishing conditions. However, a new copper-tantalum-based superalloy infused with lithium is pushing the boundaries of what’s possible, offering unprecedented strength and thermal stability. Key Developments in Superalloy Design • New Alloy Composition • Researchers have engineered a copper-tantalum-lithium superalloy capable of performing at up to 800°C (1,472°F). • This is a notable departure from traditional nickel-based alloys, signaling a potential shift in material science approaches. • Nanoscale Innovation • The material leverages nanoscale engineering techniques to create a stable, high-performance microstructure. • This fine structural control allows the alloy to maintain mechanical integrity under intense thermal and mechanical stress. • Cross-Institutional Collaboration • The research was conducted by a coalition of U.S. universities and the U.S. Army Research Laboratory, combining expertise from both academic and defense sectors. • Broad Industry Relevance • Beyond aerospace and defense, this alloy could benefit fusion energy research, where materials must survive temperatures exceeding those of the Sun. • It also holds potential for high-efficiency turbines, spacecraft, and advanced propulsion systems. Why This Advancement Matters This copper-tantalum superalloy marks a major milestone in high-performance material development. Its ability to resist extreme heat without degrading could lead to lighter, stronger, and more efficient aircraft and engines, improving fuel efficiency and durability. It may also provide a critical material foundation for future fusion energy reactors and next-generation military technology. As researchers refine nanoscale alloy design, this breakthrough underscores the growing role of nanotechnology and cross-disciplinary research in solving complex engineering challenges.

3𝐃 𝐅𝐢𝐛𝐞𝐫 𝐓𝐡𝐞𝐫𝐦𝐚𝐥 𝐏𝐫𝐨𝐭𝐞𝐜𝐭𝐢𝐨𝐧: 𝐄𝐧𝐠𝐢𝐧𝐞𝐞𝐫𝐢𝐧𝐠 𝐌𝐚𝐭𝐞𝐫𝐢𝐚𝐥𝐬 𝐓𝐡𝐚𝐭 𝐒𝐮𝐫𝐯𝐢𝐯𝐞 3,000°𝐂 As aerospace, hypersonic vehicles, fusion systems, and advanced industrial processes push the limits of temperature, conventional insulation materials are no longer sufficient. One emerging solution is 3D fiber thermal protection structures, engineered to withstand extreme thermal environments exceeding 3,000°C while maintaining low weight and structural integrity. The concept combines three critical layers: (1) 𝐒𝐚𝐜𝐫𝐢𝐟𝐢𝐜𝐢𝐚𝐥 𝐀𝐛𝐥𝐚𝐭𝐢𝐨𝐧 𝐋𝐚𝐲𝐞𝐫 The outer layer intentionally erodes under extreme heat, carrying thermal energy away from the structure and protecting underlying materials. (2) 3𝐃 𝐅𝐢𝐛𝐞𝐫 𝐀𝐫𝐜𝐡𝐢𝐭𝐞𝐜𝐭𝐮𝐫𝐞 A three-dimensional woven or entangled fiber network creates an ultra-lightweight structure with exceptional thermal resistance and mechanical strength. (3) 𝐋𝐢𝐠𝐡𝐭𝐰𝐞𝐢𝐠𝐡𝐭 𝐈𝐧𝐬𝐮𝐥𝐚𝐭𝐢𝐨𝐧 𝐂𝐨𝐫𝐞 The porous internal structure traps air and minimizes heat conduction, dramatically reducing heat transfer to the protected surface. Why It Matters These advanced thermal protection systems are being investigated for: • Hypersonic vehicles • Re-entry spacecraft • Rocket nozzles • Fusion energy systems • High-temperature industrial furnaces • Advanced energy infrastructure The combination of low density, high temperature capability, and thermal shock resistance makes 3D fiber composites one of the most promising material technologies for next-generation extreme-environment applications. As engineering pushes beyond traditional temperature limits, materials science is becoming just as important as propulsion, power electronics, and cooling technologies. 𝐑𝐞𝐟𝐞𝐫𝐞𝐧𝐜𝐞𝐬: NASA Thermal Protection Systems (TPS) Research NASA Ames Research Center – Ablative Materials Development European Space Agency (ESA) – Thermal Protection Materials for Re-entry Vehicles German Aerospace Center (DLR) – Ceramic Matrix Composites and Thermal Protection Systems AIAA Journal of Thermophysics and Heat Transfer Carbon-Carbon Composites and Ultra-High Temperature Ceramics (UHTCs) Research Literature #MaterialsEngineering #ThermalProtection #Hypersonics #AerospaceEngineering #FusionEnergy #AdvancedMaterials #Composites #HeatTransfer #Engineering #Innovation #FutureTechnology

Stainless Steel - Mo Molybdenum plays a crucial role in the metallurgy of stainless steels, fundamentally altering both their microstructure and corrosion resistance properties. In the microstructure, Mo acts as a ferrite stabilizer and provides solid solution strengthening to the matrix, enhancing both yield and tensile strength while maintaining good ductility. At high temperatures, it can promote the formation of sigma phase, which needs to be carefully controlled during processing. The most significant impact of Mo is on corrosion resistance, particularly in chloride-containing environments. It strengthens the passive chromium oxide (Cr2O3) film by concentrating in the passive layer and forming protective molybdates (MoO4²⁻), which significantly enhance the stability of the passive film against breakdown. The presence of Mo in stainless steels also dramatically improves their resistance to pitting and crevice corrosion by increasing the pitting potential and decreasing pit propagation rates. It works synergistically with chromium and nitrogen to enhance overall corrosion resistance. In terms of chemical effects, Mo reduces the rate of chromium depletion at grain boundaries, helping prevent sensitization in austenitic grades. This is particularly important in applications involving reducing acids like sulfuric acid. The element also contributes to improved high-temperature performance by increasing creep resistance, making Mo-containing grades suitable for elevated temperature applications. When Mo is added to stainless steels, it enhances the repassivation rate after any breakdown of the passive film and reduces metal dissolution rates in active states. This is especially important in crevice conditions where maintaining passivity is crucial. The combination of these effects makes Mo an essential alloying element in higher-grade stainless steels, particularly in the 316 and 317 series, where its content ranges from 2-4%. These grades find extensive use in chemical processing, marine environments, and other applications where superior corrosion resistance is required. The increased cost of Mo-containing grades is justified by their significantly enhanced performance in aggressive environments where standard stainless steels would fail.

Electric Heating 5: Very High Temperatures As an engineer who spent most of his career designing equipment to push the limits of chemical process technology, one thing that I couldn’t miss is the fact that the safe allowable stress values for all metallic materials and alloys, basically drop off a cliff around 800 C, limiting their ability to be used to support things or resist pressure.  The reason for this is “creep”, the tendency of alloys to change their shape over time even under small amounts of stress. We contend with this problem in industry in several ways. One is to manipulate conditions so that the mean temperature of the metal is kept to a reasonable level by playing games with heat transfer resistances. This is how an ordinary steel tube can be kept safe in a heat recovery steam generator, when one face of the tube is exposed to very hot gas or even to a flame. Another is to keep the supporting metal cool by using a refractory material on the hot side. The refractory can be "hard", to resist erosion and other wear and tear, or "insulating", or a compromise. The cold side must remain exposed or in some cases, must be actively cooled. And a third, when we need to transfer heat at very high temperatures, is to use tubes made of superalloys and just realize that they will eventually fail due to creep and need replacement.  That’s the strategy used in steam reformers, where the tubes operate at temperatures well beyond the limits of the normal design codes for pressure equipment. Failing tubes are literally pinched off inside the furnace while the unit continues to operate. A key limiting factor for electric heating therefore is the strength of materials at high temperatures. And there are several solutions: a)     Use superalloys: FeCrAl alloys (i.e. tradename Kanthal) are king here, but they are difficult to fabricate. They are among the best, most durable choice for heating wires used inside heating elements, but it’s tough to make a whole heat exchanger out of FeCrAl b)    Use refractory metals: molybdenum is the frequently reached for material here, but it too has serious issues other than just its cost. The elements, after the first heating, become brittle c)     Use nonmetals: heating elements can be made of silicon carbide, molybdenum disilicide, graphite and other nonmetallic materials. Each of these has its own upper temperature limit, and a set of conditions which kill them The last option is to switch to another method of electric heating- the subject of future posts.

Low Alloy Steel P11 vs P22 — Key Differences 🔥 🌎 Global Equivalents P11: UNS K11597 – USA | EN 1.7715 (13CrMo4-5) – EU | JIS STPA23 – Japan | GB/T 12CrMo – China | KS STPA23 – South Korea P22: UNS K21590 – USA | EN 1.7380 (10CrMo9-10) – EU | JIS STPA24 – Japan | GB/T 12Cr2Mo1 – China | KS STPA24 – South Korea ⚗️ Chemical Composition : Element — P11 (%) — P22 (%) — Impact C: 0.05–0.15 | 0.05–0.15 | Strength, hardenability Cr: 1.00–1.50 | 1.90–2.60 | Oxidation & creep resistance Mo: 0.44–0.65 | 0.87–1.13 | High-temp strength Mn: ≤1.00 | ≤0.60 | Toughness Si: 0.50–1.00 | 0.20–0.50 | Oxidation resistance P: ≤0.025 | ≤0.025 | Weldability S: ≤0.025 | ≤0.025 | Toughness 🔥 High-Temperature Performance P11: Moderate creep strength | ~540–560°C P22: Higher creep strength | ~565–600°C Reason: Higher Cr & Mo → improved oxidation resistance & creep life. 🏭 Applications P11: Boilers | Reheaters | Economizers | Medium-temp piping 👉 Cost-effective for moderate service P22: Power plants | Superheaters | High-pressure steam lines | Petrochemical heaters 👉 Suitable for high-temperature & high-pressure duty ⚠️ Key Challenges P11: Limited creep strength at higher temperatures Risk of accelerated oxidation in harsh environments Requires strict control of PWHT for weld integrity P22: Higher alloy content → higher cost More sensitive to welding heat input Hardness control and PWHT uniformity critical to avoid cracking Longer lead times for fittings in some regions 🧩 Key Takeaways ✔ P22 provides superior high-temperature performance due to higher Cr & Mo ✔ P11 remains a cost-effective option for moderate temperature systems ✔ Proper material selection impacts reliability, creep life & lifecycle cost ✔ Welding, PWHT, and hardness control are critical challenges for both grades ✔ Choose based on design temperature, pressure, oxidation conditions & budget 💡 Alloy Steel P11 vs P22 — Informed selection ensures safety, reliability & optimized cost. ===== For more QHSE and material engineering insights, follow 👉 Govind Tiwari,PhD #quality #hse #qhse #qa #qc #iso9001 #astm #asme #asnt #api #aws

🔎 Material Selection for Piping Systems – A Strategic Engineering Decision, Not Just a Specification Whether you’re working on refineries, offshore platforms, FPSOs, power plants, or process facilities, the wrong material can lead to corrosion failures, leaks, shutdowns, and massive financial losses. Here’s how seasoned engineers approach piping material selection 👇 1️⃣ Start With the Process – Not the Material Before thinking carbon steel or stainless steel, define: 🔹Fluid type (hydrocarbon, water, steam, acid, slurry) 🔹Operating temperature 🔹Design pressure 🔹Corrosive components (H₂S, CO₂, chlorides, oxygen) 🔹Flow velocity & erosion risk 🔹Phase (gas / liquid / multiphase) 🔹Codes like ASME B31.3 and API standards provide pressure-temperature limits — but corrosion and lifecycle define long-term success. 2️⃣ Carbon Steel – The Workhorse (When Conditions Allow) Most commonly used due to: 🔹Strength 🔹Availability 🔹Cost-effectiveness 🔹Ease of fabrication However: 🔹Not suitable for corrosive environments without coating/lining 🔹Susceptible to CO₂ corrosion 🔹Requires corrosion allowance 🔹Standards like ASTM International define grades such as A106 for high-temperature service. 3️⃣ Stainless Steel – Corrosion Resistance With Caution Grades like: 🔹304 / 304L 🔹316 / 316L 🔹Duplex / Super Duplex Offer: 🔹Better corrosion resistance 🔹Lower maintenance 🔹Improved lifecycle performance But beware of: 🔹Chloride-induced stress corrosion cracking 🔹Sensitization 🔹Higher cost For chloride environments, Duplex often outperforms austenitic grades. 4️⃣ Alloy Steels – For High Temperature & High Pressure For services like: 🔹Steam lines 🔹Power plants 🔹High-temperature reactors Alloy steels with Cr-Mo compositions provide: 🔹Creep resistance 🔹Elevated temperature strength 🔹Oxidation resistance 5️⃣ CRA & Special Materials – When Failure Is Not an Option In offshore & sour service environments: 🔹Inconel 🔹Monel 🔹Hastelloy 🔹Titanium Standards like NACE International (MR0175 / ISO 15156) guide material selection in H₂S environments to prevent sulfide stress cracking 6️⃣ Non-Metallic Options 🔹FRP 🔹HDPE 🔹PVC 🔹GRE Used in: 🔹Utility lines 🔹Seawater systems 🔹Chemical services Lightweight, corrosion resistant, but temperature & pressure limitations must be respected. 7️⃣ Key Factors Professionals Never Ignore ✔ Corrosion allowance ✔ Design life ✔ Fabrication & weldability ✔ Inspection & NDT feasibility ✔ Availability & procurement lead time ✔ Lifecycle cost (not just CAPEX) ✔ Client specification hierarchy Final Thought 💡 Material selection is a balance between: Process Requirements + Code Compliance + Corrosion Engineering + Economics ✨ Found this helpful? 🔔 Follow me Krishna Nand Ojha and my mentor Govind Tiwari, PhD, CQP FCQI for insights on Quality Management, Continuous Improvement & Strategic Leadership Let’s grow and lead the quality revolution together! 🌟 #Piping #MaterialSelection #EPC #Corrosion #QAQC #Engineering

The difference between Inconel 625 & Inconel 825 Inconel 625 and Inconel 825 are two nickel-based superalloys commonly used in industrial projects. While both alloys exhibit excellent corrosion resistance and high-temperature strength, there are important distinctions to consider when selecting the appropriate material for a specific project. One key difference between Inconel 625 and Inconel 825 lies in their performance at elevated temperatures. Inconel 625 boasts a higher melting point of 1093°C compared to Inconel 825's melting point of 950°C. Consequently, Inconel 625 maintains its strength for longer periods at high temperatures, while Inconel 825 demonstrates superior stress fracture strength, allowing it to resist cracking under cyclic loading at temperatures up to 649°C. Regarding applications, both alloys find usage in chemical processing equipment, pipeline, heat exchangers, pumps, valves, and petroleum refining equipment, where exposure to high temperatures and corrosive environments is common. However, due to its higher melting point and superior stress-break strength, Inconel 625 is typically employed in more demanding applications like gas turbines and nuclear reactors. In contrast, Inconel 825 is often suitable for less demanding applications such as exhaust manifolds and chemical processing equipment. The chemical compositions of the alloys also differ. Inconel 625 is an austenitic nickel-chromium-molybdenum alloy with 9% nickel, 22% chromium, and 3% molybdenum, along with small amounts of manganese, silicon, iron, and carbon. On the other hand, Inconel 825 is an austenitic nickel-iron-chromium alloy with 38% nickel, 20% iron, 2.5% chromium, and small amounts of manganese, silicon, copper, and titanium. In terms of mechanical properties, tensile strength is a crucial factor. Inconel 625 has a tensile strength of 862 MPa, while Inconel 825 exhibits a tensile strength of 690 MPa. Yield strength, which indicates the stress at which plastic deformation starts, is 655 MPa for Inconel 625 and 517 MPa for Inconel 825. Elongation, a measure of a material's ability to deform before breaking, is 30% for Inconel 625 and 20% for Inconel 825. Additionally, the density of Inconel 625 is 8.44 grams per cubic centimeter, while Inconel 825 has a density of 8.08 grams per cubic centimeter. When deciding between Inconel 625 and Inconel 825, the choice hinges on the specific application requirements. Inconel 625 is preferable for high-temperature strength and demanding applications, while Inconel 825 may be more suitable for lightweight scenarios requiring enhanced corrosion resistance. Other factors like cost and material availability should also be taken into consideration.

🏭 Material Selection in Piping – More Than Just Steel 1) Why Material Matters In piping systems, material selection is the backbone of safety and reliability. The wrong choice leads to corrosion, cracks, leaks, or even catastrophic failure. Every project specification defines materials based on design pressure, design temperature, fluid type, and corrosion allowance. 2) Common Materials and When to Choose Them 🔹 Carbon Steel (CS) ASTM A106 Gr.B / Gr.C (Seamless pipes) – general service, high temperature/pressure in refineries and process piping. ASTM A53 Gr.B (Seamless/ERW pipes) – utility and low/medium service lines. ASTM A234 WPB (Butt-weld fittings) – elbows, tees, reducers in CS lines. ASTM A105 (Forged flanges) – standard flanges for CS piping systems. ✅ Choose when fluid is non-corrosive, cost is critical, and temperature <425°C. 🔹 Low-Temperature Carbon Steel (LTCS) ASTM A333 (pipes) and ASTM A350 LF2 (forged flanges/fittings). Impact-tested for brittle fracture resistance. ✅ Choose for cryogenic or low-temperature service (e.g., LNG, refrigerated storage, arctic service). 🔹 Stainless Steel (SS) ASTM A312 TP304/TP316 (pipes) – corrosion-resistant. ASTM A403 WP304/316 (fittings) and ASTM A182 F304/316 (flanges). 316 grade contains molybdenum for chloride resistance (seawater, brine, chemical plants). ✅ Choose when fluid is corrosive, in high humidity, or with chlorides present. 🔹 Alloy Steels (High-Temperature Service) ASTM A335 P11, P22, P91 (pipes) – chromium-molybdenum alloys. Suitable for superheaters, boilers, and high-temperature headers. ✅ Choose for temperatures above 425°C, steam lines, and power plant services. 🔹 Line Pipe (Transmission Pipelines) API 5L (Grades B, X42, X52, X65, X70, …). Designed for long-distance oil & gas transmission. ✅ Choose for cross-country pipelines and transport of hydrocarbons. 🔹 Pressure Vessel Plates & Heads ASTM A516 Gr.60/70 – for shells and heads of pressure vessels. ✅ Choose for high-pressure vessels in refineries and gas plants. 🔹 Bolting Materials ASTM A193 B7 (stud bolts) + ASTM A194 2H (nuts) – high temperature/pressure. ASTM A320 L7 (low-temp bolts) – for cryogenic/low temperature service. ✅ Choose based on the service temperature and flange material compatibility. 3) Codes and Standards to Reference ASME B31.3 – Process Piping (defines allowable stresses, material groups). ASTM specifications – define exact chemical and mechanical properties. ASME B16.5 / B16.11 / B16.34 – for flanges, forged fittings, and valves (material + class). 4) Common Mistakes to Avoid Confusing A105 (forged flanges) with A106 (seamless pipe) – totally different applications. Selecting CS for corrosive or chloride-rich services → premature failure. Ignoring impact test requirements for low-temp service. Mixing up Class (pressure rating) with Schedule (wall thickness).

Inconel and Incoloy are both nickel-based alloys widely used in oil & gas, petrochemical, offshore, and high-temperature applications. Although they may look similar, their chemical composition, mechanical properties, and service applications are quite different. Selecting the wrong alloy can lead to: ❌ Corrosion failure ❌ High-temperature damage ❌ Cracking issues ❌ Costly shutdowns ━━━━━━━━━━━━━━━ 🔹 What is Inconel? Inconel is a nickel-chromium-based alloy designed for: ✔ High temperature resistance ✔ Severe corrosion environments ✔ Oxidation resistance ✔ High-pressure service Common Grades: ✔ Inconel 625 ✔ Inconel 718 ✔ Inconel 825 Typical Applications: ✔ Offshore piping ✔ Cladding & CRA overlay ✔ Heat exchangers ✔ Turbine components ✔ Sour service systems ━━━━━━━━━━━━━━━ 🔹 What is Incoloy? Incoloy is also a nickel-based alloy but contains a higher percentage of iron. It is mainly used for: ✔ Moderate to high temperature service ✔ Good corrosion resistance ✔ Cost-effective alloy applications Common Grades: ✔ Incoloy 800 ✔ Incoloy 800H ✔ Incoloy 825 Typical Applications: ✔ Heat treatment equipment ✔ Boilers ✔ Pressure vessels ✔ Chemical processing systems ━━━━━━━━━━━━━━━ 🔹 Main Difference ✔ Inconel → Higher nickel content & better extreme corrosion resistance ✔ Incoloy → Higher iron content & more economical for moderate service conditions ━━━━━━━━━━━━━━━ 🔹 Chemical & Mechanical Requirements Important verification activities include: ✔ Chemical composition analysis ✔ Tensile strength verification ✔ Yield strength testing ✔ Hardness testing ✔ Impact testing when required ✔ Corrosion resistance verification Applicable standards may include: ✔ ASTM B163 ✔ ASTM B444 ✔ ASME Section II ✔ NACE MR0175 / ISO 15156 ━━━━━━━━━━━━━━━ 🔹 Welding Requirements Welding nickel alloys requires strict process control to avoid cracking and contamination. Key welding requirements: ✔ Qualified WPS & PQR according to ASME Section IX ✔ Controlled heat input ✔ Proper filler metal selection ✔ Surface cleanliness ✔ Interpass temperature control ✔ PT examination after welding ✔ Ferrite and PMI verification when required Common filler materials: ✔ ERNiCrMo-3 ✔ ERNiCr-3 ━━━━━━━━━━━━━━━ Good material selection is not only about strength. It is about corrosion resistance, temperature capability, weldability, and long-term reliability. Understanding the difference between Inconel and Incoloy helps engineers select the right material for the right service condition. #Inconel #Incoloy #Welding #QAQC #NickelAlloys #OilAndGas #ASME #NACE #Inspection #CorrosionResistance #MaterialsEngineering #Fabrication #Engineering #QualityManagement © Abdelrahman Hamdy