4Cr13 stainless steel is a high carbon content (0.35-0.45 %) only a little bit of waterproof, acid-resistant stainless steel is almost no ability, due to the air and water acid contamination, this type of stainless steel in many occasions are easy to rust, and high hardness, easy to brittle fracture;
304 Stainless steel is the U.S. grade, equivalent to China's 0Cr18Ni9, its carbon content is less than or equal to 0.035, not only increased the nickel content, but also the buckwheat and nickel content are very high, there is a strong waterproof acid resistance, good toughness, not easy to crack.
Stainless steel: 4Cr13
Standard: GB/T 1220-1992
●Characteristics and scope of application:
4Cr13 Characteristics After hardening, it is a little bit higher hardness than 3Cr13, good corrosion resistance.
Used as higher hardness and high abrasion resistance of hot oil pumps, valve plates, valve bearings, medical equipment, springs and other parts.
●Chemical composition:
Carbon C: 0.36 ~ 0.45
4Cr13 stainless steel
Silicon Si: ≤ 0.60
Manganese Mn: ≤ 0.80
Sulphur S: ≤ 0.030
Phosphorus P: ≤ 0.035
Cr: 12.00 ~ 14.00
Cr: 12.00 ~ 14.00
Cr: 12.00 ~ 14.00
Cr: 0.00~1.00 14.00
Nickel Ni: allowed to contain ≤ 0.60
●Mechanical Properties:
Hardness: annealed, ≤ 201HB; quenched and tempered, ≥ 50HV
●Heat Treatment Specification and Metallurgical Organization:
Heat Treatment Specification:
Heat Treatment Specification:
1) Annealing, 800 ~ 900 ℃ slow cooling or about 750 ℃ fast cooling; 2) Quenching. 1050 ~ 1100 ℃ oil cooling; 3) tempering, 200 ~ 300 ℃ fast cooling.
Metallographic organization: organizational characteristics of martensitic type.
●Delivery status: generally delivered in heat-treated state, the type of heat treatment is specified in the contract; not specified, according to the non-heat-treated state delivery.
●Annealing
General annealing using 780-800 degrees, insulation 4-6 hours, to ≤ 50 degrees / hour, cooling to 550 degrees out of the air-cooled, isothermal annealing using 700-800 degrees of insulation 2-4 sales, and then 670-720 degrees of insulation, holding 2-4 hours, to ≤ 50 degrees / hour cold cooling to 500 degrees out of the air-cooled, annealing Hardness of 241-197HB
Product name
304 (0Cr18Ni9) stainless steel seamless pipe
Product introduction:
One production specifications (mm):?6 × 1 ~ 830 × 20 (can be customized according to customer requirements)
Two finished length (m): 5-7 (can be customized according to customer requirements), some of the longest up to 28m
Three product material: 304 (0Cr18Ni9)
Four theoretical weight (kg/m): Cr-Ni austenitic stainless steel W = 0.02491S (D-S)
Five executive standards:
National standard: GB/T14975-2002 GB /T14976-2002 GB/T13296-2007
American Standard: ASTM A312/A312M ASTM A269/269M ASTM A213/213A
German Standard: DIN2462
Japanese Standard: JIS G3463
Product Characteristics
1 Chemical Analysis:
Grade number
Chemical composition (mass fraction), %
C(Carbon)
Si(Silicon)
Mn(Manganese)
P(Phosphorus)
S(Sulfur)
Ni(Nickel)
Cr(Chromium)
Mo(Molybdenum)
Other
0Cr18Ni9
≤0.07
≤1.00
≤2.00
≤0.035
≤0.030
8.00 to 11.00
17.00 to 19.00
2, hydraulic test:
Stainless steel seamless pipe root by root hydraulic pressure test, in the specified pressure value, keep not less than 5 seconds. Pipe shall not leak or leakage, conventional supply hydraulic pressure test for P = 2SR/D (maximum not more than 20MPa).
3, corrosion resistance:
General resistance to intergranular corrosion and excellent corrosion resistance, alkali solutions and most organic and inorganic acids also have a certain degree of corrosion resistance, the supply of seamless stainless steel pipe are in accordance with the standard or the two sides agreed to the corrosion method of corrosion resistance test, there shall be no tendency to corrosion of intergranular corrosion.
4, process performance test:
Compression test. Tensile test. Flaring test. Hardness test. Metallographic test. Non-destructive testing (including eddy current and ultrasonic testing).
Product Uses
Used in acid piping, chemical equipment, heat exchanger piping, and other process equipment that comes into contact with fresh water, etc., 304 stainless steel has been used very successfully in fresh water with low chloride ion content. In general, and especially if there is a seam gap present, the limit for 304 stainless steel is 100 ppm chloride. High levels of chloride may cause crevice corrosion and pitting corrosion. Under more severe conditions, such as low pH, or high temperatures, a stainless steel with a higher molybdenum content, such as 316, would be considered.304 is susceptible to the formation of intergranular corrosion when exposed to harsh environments at temperatures ranging from 427°C- 816°C. The use of stainless steels with high molybdenum content, such as 316, would be considered.
Main Users
Boiler plants, heat exchanger plants, chemical plants, water treatment plants, etc.
Precautions
1, 304 stainless steel seamless tubes are not recommended to be used in marine environment.
2, no matter how corrosive, stainless steel in the processing and use of the process, to keep its surface clean.
For light industrial use, less maintenance is required, only the sheltered areas sometimes need to be cleaned with pressurized water. Heavy industry, on the other hand, recommends frequent cleaning to remove accumulated dust that may eventually cause corrosion and damage the surface appearance of stainless steel.
Stubborn stains and deposits can be scrubbed with a scrubbing agent and a fiber brush, sponge, or stainless steel fleece. Stainless steel lint can leave permanent scuff marks on smooth stainless steel surfaces.
Many stainless steels need to be cleaned and sanitized regularly. Equipment is usually cleaned with specially formulated caustic soda, organic solvents, and acidic solutions (such as phosphoric or sulfuric acid). Strong reducing acids (such as hydrofluoric or hydrochloric acid) may cause damage to stainless steel.
After solution cleaning, rinse stainless steel thoroughly with water
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