Recently learned, Tangshan Iron and Steel China North Vehicle Group "tailored" new varieties of high strength wire steel 60-G has been successfully applied to the front of manufacture of EMU. It is reported that the varieties of tons of steel price 1500 yuan higher than ordinary wire products. It is understood that China North Vehicle Group also expressed the hope that the intention of further strengthening cooperation with Tangshan Iron and Steel, the company's railway rolling stock and urban rail vehicles accounted for more than half of the domestic market share.
It is reported that as of November, Tangshan Iron and Steel Company gas Flux Core Welding Wire, submerged arc welding wire total sales in 2010 amounted to 33,000 tons, which is 3.7 times that of the previous year. At present, Tangshan Iron and Steel Wire Rod varieties have been formed series, submerged arc Welding Wiresthe wire rods H08MnA, H10Mn2, H10MnSi, EM12K and alloy wire hot rolled of rod ER70S-6, ER70S-3 and uniform chemical composition, good mechanical properties, and overall product quality of domestic first-class level.
Argon arc welding safety technology Argon arc in addition to manual arc welding of electric shock, burns, fire, high-frequency electromagnetic field, the electrode radiation and much stronger than the manual arc welding arc injury, welding fumes and toxic gases. The most important is the high-frequency electric and ozone. A prevention of high frequency electromagnetic field damage Produce and hazards of a high-frequency electromagnetic fields Gas tungsten arc welding and plasma arc welding and cutting, the commonly used high-frequency oscillator to excite the arc, and some AC TIG welding machine with high frequency oscillator to stabilize the arc. Welding commonly used high-frequency oscillator frequency of 200-500 kHz, the voltage of 2500-3500 V, high-frequency current intensity of 3-7 mA, the electric field strength of about 140-190 V / m. Welders long-term exposure to high-frequency electromagnetic fields can cause autonomic dysfunction and neurasthenia. The performance of general malaise, dizziness, dreaminess, headache, memory loss, fatigue, weakness, loss of appetite, insomnia and low blood pressure and other symptoms. The high frequency electromagnetic field of the reference health standard provisions of the contact of 8 hours to allow the radiation intensity of 20 V / m. It has been determined by GTAW welder various parts of the high-frequency electromagnetic field strength exceeds the standard, which the hand strength to exceed health standards for more than five times. If the arc when the high-frequency oscillator, time is short, less affected, but long-term exposure is harmful and must adopt effective protective measures. (2) the protective measures on the high-frequency electromagnetic field The â‘´ TIG arc starting and arc stability measures as far as possible with transistor pulse device, rather than high-frequency oscillation device, or used only to arc after arc ignition, immediately cut off high frequency power supply.
(2) reduce the frequency of oscillation, and change the capacitor and inductor parameters, the oscillation frequency to 30 kHz, to reduce the impact on the human body.
â‘¶ shielded Welding Cableand wire, the preparation of soft thin copper wire, the cable hose outside (including welding torch and pass to the Mig Welding Wires), and ground.
(4) due to high frequency oscillation circuit voltage is high, there must be good and reliable insulation.
Second prevention of radiation injury A source of radiation and hazards TIG and plasma arc welding and cutting use the thorium tungsten containing 1-1.2% of the thorium oxide, thorium is a radioactive material in the welding process and thorium tungsten rod contact process, the radiation impact. Radiation to the role of two forms of the human body: First, in vitro irradiation, the second is a body irradiation into the body through the respiratory and digestive systems. Cover argon arc and ion arc a lot of investigation and determination of radioactive hazardous smaller, daily consumption of thorium tungsten rods only 100-200 mg, the dose of radiation is minimal impact on the human body big. However, there are two cases must be noted: First, welding inside the container, and poor ventilation, dust radioactive particles may exceed the standard; grinding thorium tungsten rod and thorium tungsten rod location, radioactive aerosols and the concentration of radioactive dust, can meet or exceed health standards. Radioactive substances invade the body can cause chronic radiation disease, mainly in the weakened state of the general function, you can see the apparent languor, and resistance to infectious diseases decreased significantly, weight loss and other symptoms. (2) measures to prevent radiation injury (1) thorium tungsten rod should have a dedicated storage device, a large number of storage should be hidden in a metal box inside, and install the exhaust pipe.
â‘µ airtight cover welding operation should not open the hood body, the manual must be worn when the blast protective helmets, or other effective measures.
â‘¶ should be equipped with a special grinding wheel grinding thoriated tungsten rods, wheel confidential install dust removal equipment, grinders and ground debris often wet wipe out, and focus on deep processing.
(4) grinding thoriated tungsten rod should wear dust masks. Exposure to thorium-tungsten rod should wash your hands with running water and soap, and regular cleaning of work clothes and gloves.
â‘¸ Welding and Cutting Select reasonable regulations to avoid the thorium tungsten rods excessive burning.
â‘¹ as much as possible without thorium tungsten rod with cerium tungsten rod or yttrium tungsten rod, due to the latter two non-radioactive.