ASTM A519 4130 Alloy Steel Seamless Steel Tube for Mechanical
Item specifics
- OD
- 40-400MM
- WT
- 5-30MM
- Delivery condition
- QT
- Surface condition
- peeled
Review
Description
Standard
Specifications
1.A519 4130 steel tube
2.100% NDT
3.ISO9001, ISO/TS 16949
4.meet American standards
5.high accuracy
Chemical Composition
Mechanical Properties
Tests we apply to the tubes:
1) Chemical Composition Analysis
2) Mechanical Properties (Tensile strength, Yield strength,, Elongation, Hardness)
3) Technological Test (Flattening test, Flaring Test, Bending Test, Hydraulic pressure test)
4) Surface quality detection
5) Eddy-current examination
6) Visual test
Heat Treatment
Annealing of 4130 Steel
Annealing of 4130 forgings may be carried out by transferring the part straight from the forging operation to a furnace held at a suitable temperature, around 1575 º F (860º C) for annealing, holding for a suitable time then furnace cooling. In this way a structure suitable for machining may be obtained. This treatment is best used for parts with simple shapes. If the forging is such that some sections (of the forging) will finish much colder than others then a uniform structure will not be obtained and for best results a spheroidizing anneal at around 1380 º F (750 º C) may be used. It is safe to say that experience alone will decide the best type of annealing treatment to be used prior to machining.
Normalizing of 4130 Steel
This process is defined as heating a steel to a temperature above the ferrite to austenite transformation temperature, then cooling in air to a temperature well below this transformation temperature. The treatment may be carried out on forged or rolled products as a conditioning treatment prior to final heat treatment. Normalizing also serves to refine the structure of forgings that might have cooled non-uniformly from their forging operation. The nominal normalizing temperature for 4130 grade is 1650 º F (900 º C), but production experience may necessitate a temperature either 50 º F (10 º C) above or below this figure. In fact when forgings are normalized before, say, carburizing or hardening and tempering, the upper range of normalizing temperatures is used. When normalizing is the final heat treatment, the lower temperature range is used.
Hardening of 4130 Steel
This heat treatment results in the formation of martensite after quenching, thus a great increase in hardness and tensile strength, together with some brittleness. The steel should be austenitized – i.e. all micro constituents transformed to austenite – at 1500 to 1600 º F (815 to 870 º C). The actual austenitizing temperature is a function of chemical composition within the analysis range, section size and cooling method. Smaller sections of 4130 might be quenched in oil, heavier sections in water.
Tempering of 4130 Steel
Tempering is carried out to relieve stresses from the hardening process, but primarily to obtain mechanical properties required for the final application. The actual tempering temperature will be chosen to meet the required properties, and in many cases will be a matter of trial and error.
Machinability
The alloy is readily machinable. Simple shapes might be machined following a normalizing treatment, whereas more complex shapes will require annealing. For optimum machinability a coarse pearlitic structure with minimum ferrite is normally recommended.
Welding
AISI 4130 steel is also good in weldability, and the 4130 alloy may be welded by any commercial method. The material may require a post-weld stress relief heat treatment in certain instances. Low-hydrogen electrodes are recommended together with preheat at 150 – 260 º C (300 – 500 º F) to be maintained during welding, Cool slowly and stress relieve where possible.
