The corrosion resistance of these steels comes from "chromium", which ranges from 11.5 to 18%. The higher the chromium content, the higher the carbon content to ensure the composition of martensite during heat treatment. The above three types of 440 stainless steel are very It is rarely considered as an application requiring welding, and the 440 type of molten metal is not easy to obtain. The improvement of the standard martensitic steel shaft is rich in additional elements such as nickel, molybdenum, vanadium, etc. It is mainly used to increase the limited allowable working temperature of standard steel to above 1100K. When these elements are added, the carbon content is also As the carbon content increases, the problem of avoiding cracks in the hardened heat affected zone of the weld becomes more serious.
Martensitic stainless steel can be welded under annealing, hardening and hardening and tempering. No matter what the original state of the steel is, a hardened martensite zone will occur in the adjacent weld bead after welding. The hardness of the heat affected zone is mainly It depends on the carbon content of the base metal. When the hardness increases, the toughness decreases, and this area becomes more prone to cracking, preheating, and controlling the interlayer temperature. It is the most useful way to avoid cracking. Good properties require post-weld heat treatment. Martensitic stainless steel is a type of stainless steel whose function can be adjusted by heat treatment (quenching, tempering), in general, it is a type of hardenable stainless steel. This characteristic determines that this type of steel must have two basic conditions: First, there must be an austenite phase zone in the equilibrium phase diagram. After long-term heating in the temperature range of this zone, the carbide is dissolved into the steel. To form martensite by quenching, that is, the chemical composition must be controlled in the γ or γ+α phase region. The second is to make the alloy form a passivation film resistant to corrosion and oxidation, and the chromium content must be more than 10.5%. According to the difference of alloy elements, it can be divided into martensitic chromium stainless steel and martensitic chromium nickel stainless steel. The main alloying elements of martensitic chromium stainless steel are iron, chromium and carbon. The iron-rich part of the Fe-Cr system phase diagram, such as Cr is greater than 13%, there is no γ phase. Such alloys are single-phase ferrite alloys, and martensite cannot occur under any heat treatment system. Austenitic constituent elements are added to the Fe-Cr binary alloy to expand the γ phase region. For martensitic chromium stainless steel, C and N are useful elements. The addition of C and N elements allows the alloy to allow higher chromium content. Among martensitic chromium stainless steels, in addition to chromium, C is another most important element. In fact, martensitic chromium stainless heat-resistant steel is a class of ternary alloys of iron, chromium, and carbon.
Shenzhen Hekai Hardware Rotary Shaft Processing Custom Manufacturer was established in 2005. We are mainly engaged in R&D, design, processing, and production of rotary shafts. We have a stamping center and our own molds for rotating shafts. The main products are: notebook shafts, DV shafts, LCD shafts , Phone shaft, mobile phone shaft, table lamp shaft, learning machine shaft and medical equipment shaft, etc., support wholesale, customization, processing. Since the establishment of the company, we are devoted to the innovation of precision hardware shaft and supporting cable products, has become a bead One of the shaft manufacturers with certain strength in the triangle area.
Contact: Mr. Wu Linmao phone:0086 0755 28835296-868 mobile phone: 013510815393 fax:0086 0755 28832846
address:Building 15, Sanyang Lake Industrial Zone, Pingshan Street, Pingshan New District, Shenzhen, Guangdong, China
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