In the finished product bundle of steel warehouse, double sampling for re-inspection, the steel cooling bed in the rolling mill production line is automatically bundled and packed, each bundle weighs about Zt, and the steel is packed in bundles and the temperature is between 20 °C and 300 °C. In the indoor warehouse. After 7 days, the batch was double sampled in a steel library where the steel had cooled to room temperature. After re-examination of the mechanical properties of the steel, the reduction of the area of ​​the steel has been greatly improved, and the hydrogen content has also decreased a lot. The average calculated area shrinkage was 28% higher than the first test and the hydrogen content was reduced by 47%. It can be seen that in the process of stacking and cooling the steel under the cold bed, the hydrogen content in the steel can be greatly reduced. The face is not tightly centered, and the octahedral gap radius is not as large as the face centered cubic. Therefore, the solubility in austenite is larger than that in ferrite, and after the end phase transformation is completed, it will diffuse into the austenite with a large intermediate solubility until it is concentrated in the center. The white point is formed from 150 ° C to 200 ° C to room temperature. When the steel reaches the finishing platform, the temperature is between 200 ° C and 300 ° C. Although the core of the steel contains a certain amount, no white spots are formed. At this time, if the sample is placed on the side of the sample separately, the steel will be rapidly cooled to room temperature, and if the steel contains an excessive amount, it will aggregate under internal stress to form a sawtooth crack, which is a white point. When the steel is bundled at 200 ° C - 300 ° C and stacked in the indoor warehouse layer, it will slowly cool to room temperature. Then the internal stress of the steel will be greatly reduced, even if there is an excess, it is difficult to form white spots; at the same time, the ferrite in the steel is body-centered cubic (bcc), and its close-packed structure is not as compact as the face-centered cubic structure, at 30 ° C at 20 ° C Long-term insulation of atoms can easily diffuse out of the steel and reduce the content of steel. Therefore, when double sampling and re-inspection in the steel product finished product pile, the steel section shrinkage rate has increased a lot, and its content has also dropped a lot. Once the white point in the steel is formed, there is a sawtooth crack, which is called irreversible white point.
This method cannot eliminate this defect. There is no vacuum degassing device in the company's steelmaking production. The hydrogen content is between (4.0-6.5) by sampling and analyzing the 6osiZMn steel in the crystallizer. In the rolling steel production process, the billet is in a high-temperature austenite (y) state, and the middle of the billet will spread outward as the billet rolling size is continuously reduced. However, since the unit cell structure of Fe in the austenite (Y) state is face-centered cubic (fcC structure), the arrangement of the close-packed surface is quite close, and the octahedral gap is large, so it is difficult to diffuse out. At the same time
Product name:Compression Spring Steel Wire
Standards:
DIN 17223-1 Round Steel Wire For Springs
DIN EN 10270-1 Steel Wire For Mechanical Springs
GB 3206-82 Carbon Constructional Quality Steel Wire
JIS G 3521-1991 Hard Drawn Steel Wire
GB 4357-89 Carbon Spring Steel Wire
YB/T 5220-93 Carbon Steel Wire For Non-Mechanical Springs
Diameter: 0.20mm-12.50mm
Usages: compression spring.
Material: 30MnSi, 62A,62B, 60, 65, 65Mn, 70, 75,72A, 72B, 77A, 77B, 80,82A, 82B
Compression Spring Steel Wire
Compression Spring Steel Wire,Conical Spring Wire,Innerspring Steel Wire,Trampoline Spring Steel Wire
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