EQ70 is a kind of high strength steel plate for offshore platform. The commonly used brands are EQ70 and [SCALE STEEL]EQ70-Z35.
1. Chemical Composition (Melting Analysis, %)
Chemical composition (melting analysis, %) shall conform to the following table. Ni, Mo, Nb, V, Zr, Cu, B should be reported.
For EQ70-Z35, S is not greater than 0.005%. [SCALE STEEL]
C Si Mn P S N
≤0.18 ≤0.55 ≤1.60 ≤0.025 ≤0.025 ≤0.020
2. Size, Shape, Weight and Allowable Deviation, Surface Quality Should Comply with ASTM A6/A6M.
3. Delivery State of EQ70 Marine Steel: Quenching + Tempering.
4. Mechanical Properties of EQ70 Marine Steel:
Mechanical properties should [SCALE STEEL]conform to the following table. Eq70-z35 should also comply with the provisions of GB/T5313.
Yield Strength N/mm2 Tensile Strength N/mm2 Elongation
≥690 770～940 ≥14 纵向 ≥69
5. Ultrasonic Inspection:
The steel plate is tested by ultrasonic method according to ASTM A578/A578M, and the qualified grade is C.
6. Inspection Rules, Inspection Items and Test Methods
Should comply with [SCALE STEEL]certification sampling related notice.
7. Mark and Quality Certificate
Should comply with ABS Classification Society regulations.
8. Relevant Steel Grades with EQ70 Steel:
Marine engineering steel NVE690 is EQ70 grade steel of American standard. After testing, the performance indexes of the steel can meet the requirements of users. This steel grade is the first Marine steel successfully [SCALE STEEL]developed by Wugang, marking a new breakthrough in the research and development of Marine steel.
Marine platforms (including oil production platforms and drilling platforms) are subject to the erosion and destruction of natural forces such as waves, submarine earthquakes and low temperature, so the technical specifications of steel are very high, and the technical standards of steel used in key parts such [SCALE STEEL]as rack and pile leg are more demanding. In order to realize the localization of steel for offshore platform, Wugang began to develop 140mm thick tempered and tempered high strength steel A514GrQ in 2008, which took 10 months to achieve success. At the same time of mass production of 140mm thick A514GrQ, Wugang quickly put into the research and development of the steel with greater thickness. In 5 months, we have developed A514GrQ of 150mm, 180mm, 215mm and other thickness specifications, and successfully passed the CERTIFICATION of [SCALE STEEL]ABS Classification Society. This means that China's offshore platform with high strength steel series all thick plate, wugang all can produce independently.
When proceeding with heat treatment (quenching and tempering), SUS420J2 has excellent corrosion resistance, polishing performance, high strength and wear resistance, suitable for manufacturing plastic mold bearing high load, high [SCALE STEEL]wear resistance and under the action of corrosive media.
Standard of SUS420J2 Stainless Steel: JIS G 4303:2005
SUS420J2 stainless steel is martensitic type stainless steel, this kind of stainless has good machining performance, the hardness of 3Cr13 material below HRC30 after quenching and tempering treatment is better machinability, [SCALE STEEL]easy to achieve better surface quality. While hardness is greater than HRC30 processed parts, although the surface quality is better, but the tool is easy to wear. Therefore, in the material into the factory, the first quenching and tempering treatment hardness reached HRC25 ~ 30, and then the cutting process. SUS420J2 has high hardness after quenching, used as cutting tools, nozzle, seat, valve, etc.
The density of SUS420J2 is 7.75g/cm3.
C 0.26-0.40Mn ≤ 1.00Si ≤1.00,P≤ 0.040s ≤ 0.030Cr 12.00-14.00Ni ≤0.60 [SCALE STEEL]
Mechanical Properties of SUS420J2:
Yield strength (N/mm2) ≥540
Tensile strength (N/mm2) ≥740
Elongation EL (%) ≥12
HRC hardness 50 to 55
Hardness acuity HBW217
Area shrinkage rate /% ≥40
Charpy impact value/(J/cm2) ≥29
Heat treatment / ℃
Quenching [SCALE STEEL]temperature 1000~1050℃
Tempering temperature 200~500℃
Rust resistance, corrosion resistance, avoid heat treatment, will not produce heat treatment caused by the deformation, ultra mirror [SCALE STEEL]processing performance, in the state of annealing has good mechanical processing performance.
SUS420J2 Stainless is widely used in fluorinated plastics with corrosive gases or corroded plastic moulds with[SCALE STEEL] added flame retardants, etc.
‘APPLE’ of the United States introduced a titanium laptop many years ago. The computer not only has advanced performance, but its [SCALE STEEL]case is made of titanium. While many laptops claim to have Titanium shells, most are Titanium plated, this Titanium Power Book G4 laptop has a Grade 1 industrial Titanium shell. It is also the world's first pure titanium computer casing. The overall thickness of the computer is 25.4mm and the weight is 2.4kg. Titanium used in computer shell in the titanium industry and computer industry have a great influence. Titanium shells delivered in grey colour can be oxidized to red, purple and yellow.
Apple's titanium-clad computer is expected to challenge SONY's magnesium-clad model, which is not only beautiful in appearance but also has excellent performance. Compared with magnesium, titanium has high tensile strength (106.3GPa for titanium and 44.4GPa for magnesium) and low thermal conductivity. Titanium is 17W/m.K, [SCALE STEEL]only one tenth of that of magnesium (159W/m.K). Therefore, the titanium shell can maintain strength while realizing thin wall, inhibit heat diffusion from hardware and prevent heating on the bottom.
IBM's Think Pad A series (A20p) and T series (T20) laptop cases use titanium composite materials, which not only improve the strength and seismic [SCALE STEEL]performance of the case, but also make the computer thinner and lighter. HP's X16-1201TX and X16-1301TX notebooks also use titanium shells.
Fujitsu of Japan makes a small A5, 890GB lightweight laptop that uses [SCALE STEEL]pure titanium. The company also uses titanium in the casing of its INTERTOP CX300 laptop.
Titanium alloy has the advantages of low density, high specific strength, good toughness, good corrosion resistance and good machining performance, [SCALE STEEL]which makes it an ideal structural material for aerospace engineering.
Titanium alloy is a new kind of structural material, it has excellent comprehensive properties, such as low density (~4.5g cm-3), high specific strength and specific fracture toughness, good fatigue strength and crack propagation resistance, good low temperature toughness, excellent corrosion resistance, the highest operating temperature of some titanium alloys is 550ºC, expected up to 700ºC. Therefore, it is increasingly[SCALE STEEL] widely used in aviation, chemical industry, medical treatment, shipbuilding and other industrial sectors, rapid development.
Another significant characteristic of titanium is strong corrosion resistance, which is the affinity of titanium to oxygen is particularly large, can generate a layer of dense oxide film on its surface, can protect titanium from medium corrosion. Titanium metal can form passivated oxide film on the surface in most aqueous solutions. [SCALE STEEL]Therefore, titanium has good stability in acidic, alkaline, neutral salt aqueous solution and oxidizing medium, but in a certain medium, can continuously dissolve titanium oxide film on the surface, titanium in this medium will be corroded. For example, in hydrofluoric acid, concentrated hydrochloric acid, fluvial acid, and phosphoric acid, the titanium is corroded as the solution dissolves the oxide film on the titanium surface. If oxidant or some metal ions are added to these solutions, the oxide film on the titanium surface is protected.
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