Products
Low Temperature Pipe (A333 A334 Gr.6 Gr.3)
LOW TEMPERATURE PIPES
Pipe Sizes--1/4” Nominal to 42”O.D.
Wall Thickness – Schedule 10 through XXH
Low-temperature carbon steels have been developed chiefly for use in low-temperature equipment and especially for welded pressure vessels.
They are low- to medium-carbon (0.20 to 0.30%), high-manganese (0.70 to 1.60%), silicon (0.15 to 0.60%) steels, which have a fine-grain structure with uniform carbide dispersion. They feature moderate strength with toughness down to — 50°F (—46°C).
For grain refinement and to improve formability and weldability, carbon steels may contain 0.01 to 0.04% columbium. Called columbium steels, they are used for shafts, forgings, gears, machine parts, and dies and gages. Up to 0.15% sulfur, or 0.045 phosphorus, makes them free-machining, but reduces strength.
LTCS is a Nickel based alloy steel plates especially used for low temperature applications below - 150 deg F. Mainly used in cryogenic construction of space ships, low temperature application in chemical plant below -55 deg C.
SA-203 Steel Plate Grades A, B, D, E and F Nickle Alloy Steel Plates. For low temperatures (-150 deg F)
Low Temperature Carbon Steel Tubes ASTM A334 Gr.1
ASTM A333——Seamless and Welded Steel Pipe for Low-Temperature Service:
Mainly Grade
Grade 1, Grade 3, Grade 4, Grade 6, Grade 7, Grade 8, Grade 9, Grade 10, Grade 11;
Low temperature carbon steel pipe quenching temperature in A3 + (30 ~ 50) ℃, in practice, is usually set to the upper limit. High quenching temperature heat pipe can make low speed, surface oxidation reduction, and can improve work efficiency. The workpiece is uniform austenite, will require sufficient holding time. If the actual installed furnace capacity, would need to be appropriate to extend the holding time. Otherwise, there may be insufficient hardness due to uneven heating caused by the phenomenon. However, the holding time is too long, will also appear coarse grains, oxidation and decarbonization serious ills affecting quenching quality. We believe that if installed furnace is greater than the process documents, heating holding time to be extended 1/5.
Low temperature carbon steel pipe because of low hardenability, it should adopt a large cooling rate of 10% salt solution. Workpiece into the water, should hardenability, but not chilled, if 45 # precision steel chilled in brine, it is possible cracking of the workpiece, this is because when the workpiece is cooled to about 180 ℃, the austenite rapidly converted to horse s body tissue caused by excessive stress due. Therefore, when the quenching and tempering steel quickly cooled to this temperature range, the approach should be taken to slow cooling.
As the water temperature is difficult to grasp, accountable experience in operation, when the water stops dithering artifacts, you can water cooled (eg oil cooler can be better). In addition, the workpiece into the water, appropriate action should still be in accordance with the geometry of the workpiece, as regular exercise. Stationary cooling medium plus stationary workpiece, resulting in uneven hardness, stress uneven leaving large deformation of the workpiece, and even cracking.
