FAQ About SAE j2340

What is sae j2340 steel?

SAE J2340 steels are dent-resistant, high-strength and ultra-high strength commonly used in the automotive industry. SAE J2340 constitutes seven grades of continuously cast high strength automotive sheet steels that can be formed, welded, assembled, and painted in automotive manufacturing processes. These steels can be specified as hot-rolled sheet, cold-reduced sheet, uncoated, or coated by hot dipping, electroplating, or vapor deposition of zinc, aluminum, and organic compounds normally applied by coil coating.

Grades and strength levels are achieved through composition and processing. The selection of grade should be based on part configuration and strength, as well as the amount of strain induced by forming and the impact strain has on the strength achieved in the finished part.

SAE J2340 – XF grades are available with about 5% higher formability at each strength level. Steel Warehouse will gladly help you select the exact grade for your needs.

What are the advantages of sae j2340?

Compared with ordinary steel bars, sae j2340 reduces the amount of steel bars used and installed, and saves engineering materials and manpower. Moreover, sae j2340 has good mechanical properties, which ensures the quality of the project and meets the specifications and design requirements.

  1. High strength: the standard value of strength is 400MPa, and the design value of tensile strength is 360MPa.
  2. Good ductility: elongation rate ≥ 14%, in fact, the average elongation rate can reach 20%, which can save 10%-15% of steel compared with HRB335 steel bar (strength design value 300MPa).
  3. Stable energy, low sensitivity to strain aging, and greater safety reserve than HRB335 grade steel bars.
  4. Good welding performance: suitable for various welding methods.
  5. High strength-to-yield ratio: greater than 1.25, the measured value of yield strength os/standard value of strength is ≤1.30, and the seismic performance is good.
  6. Good cold bending performance.

What are the precautions for using sae j2340 steel?

(1) Labeling: sae j2340 steel label refers to: AH32, DH32, AH36, DH36, EH36, there must be a label on the steel plate and a label on the component

(2) Preheating: sae j2340 steel must be preheated before tack welding, the preheating temperature is 80C-100C, and the heat range is 5 times the thickness of the plate, but not less than 100mm.

(3) Heat preservation: 507 welding rods must be put into heat preservation tubes after they are taken out of the oven, brought into the construction site, and replaced every 4 hours.

(4) Cleaning: Before welding, impurities such as scale dirt within 30mm in width of the weld to be welded must be removed. Failure to weld in time will cause the weld and the weld to be welded in a width of 30mm to re-rust or pollute. to clean up

(5) Welding method: multilayer and multilayer interlayer temperature must be 100C, the welding direction of the same layer of welding bead must be consistent, and the welding direction of each layer is opposite, but the joints must be staggered

(6) Carefully check the smooth wire feeding and gas flow of the CO2 welding machine before welding.

What are the operating points of sae j2340?

  1. The streets with grooves in vertical or inclined positions must be welded from bottom to top. For thin plate butt joints and vertical fillet welding without grooves, downward welding can be used, and flat, horizontal and upward butt joints can be welded in the sitting direction.
  2. A reasonable welding sequence must be selected according to the structure of the workpiece to be welded and the outdoor operation when the wind speed is greater than 1M/S
  3. Fox and arc extinguishing plates with the same plate thickness of 150*150 should be installed at both ends of the butt joint
  4. For plate seams with grooves, especially for multi-pass welds, when the welding wire swings, it should stop for a while on both sides of the groove. The thickness of each layer of zigzag strips should not be greater than 4mm, so that the welds can be well fused
  5. The dirt in the hose and the splash of the nozzle should be cleaned frequently. The wire feeding hose must be straightened and not twisted when welding. The radius of the wire feeding hose should not be less than 150mm. Pure gas discharge.
  6. Correctly select the conductive resistance of the welding wire according to the diameter of the welding wire. After the conductive resistance is worn out, the aperture increases, causing unstable welding, and the conductive resistance needs to be replaced

What is the application prospect of sae j2340?

Due to the recent rapid rise in crude oil prices and the intensification of global warming, it has become an inevitable trend to use high-strength steel plates from the top to ensure both the lightweight of the car and the safety of impact resistance. However, if the pure pursuit of strength may lead to This leads to a decrease in the formability of the material itself. Therefore, the problem faced by automobile manufacturers and parts manufacturers is how to manufacture automobile parts with high-tensile steel plates, not only focusing on material supply, but also giving full attention to forming and processing.

So far, the focus of automobile lightweighting has been to reduce the wall thickness of the constituent materials and increase the strength of the materials.

In order to make high-strength steel sheets suitable for use as raw materials for automotive parts and to reduce the weight of the car body, it is necessary to increase the joint strength. Compared with spot welding, laser welding can achieve continuous welding, which can greatly improve the impact resistance in terms of static and fatigue strength; from the perspective of lightweight, it can also enhance the lightweight advantages of high-strength steel.