電焊危害（Welding hazards）

1、電焊危害（Welding hazards）Welding hazards1, what are the harmful factors in welding operation?There arc radiation, metal dust, harmful gases, high frequency electromagnetic fields, radiation and noise and other harmful factors in the process of welding, manual welding operation are harmful factors is the

2、 light radiation, metal dust and harmful gas.2. What is metal smoke?Welding fumes, including smoke and dust, during welding operations. The metal vapor generated by the electrode and the base metal during the melting (often including electrode in Fe, Mn, Si elements, Cr and Ni are lower than the boi

3、ling point of the arc column temperature) in air oxidation and condensation rapidly formed solid particle diameter less than 0.1 microns in diameter called smoke, 0.1-10 micron metal micro material called metal dust. Collectively referred to as metal smoke.The composition and concentration of metal

4、smoke depends on the welding process, welding materials and welding specifications. For example, from welding methods, the amount of soot produced by iron welding and cutting is less than that of open arc welding. From the comparison of electrode types: the titanium and fiber type and the luminous f

5、lux of the welding rod are higher, and the luminous intensity of the titanium calcium electrode is lower; the luminous quantity of the stainless steel electrode is lower than that of the carbon steel and the low alloy steel electrode.From the welding parameters, the welding current increased, light

6、quantity increases, the arc voltage increase, the soot volume increased; the polarity of the power supply also has an influence on the welding fume quantity, such as stainless steel electrode with DC welding method on luminous flux is low, but it is connected to DC electrode structure steel light la

7、rger; welding position different amounts of light is not the same. When a large amount of light welding when the welding.3, metal smoke on the human body what harm? How to protect?Long term inhalation of high concentration welding fume can cause many serious organic changes in the respiratory system

8、, nervous system and so on. As to the long-term inhalation of iron oxide, and is mixed with silica, manganese, chromium and ozone, nitrogen oxides and other irritating, promote the mixed dust and harmful gas can cause pulmonary fibrosis, pneumoconiosis. Long term inhalation of manganese and its comp

9、ounds with excess concentrations of manganese and its compounds can lead to manganese poisoning. For a long time in the sealed tank, cabin welding basic electrode, inhalation iron oxide and fluoride micro, can cause welding metal heat.Therefore, when welding, measures must be taken, such as wearing

10、masks, the use of vacuum equipment, installation of ventilation device with low dust electrode (such as GB81-76 7.5 provisions of acid electrode emission quantity of g / kg, basic electrode emission quantity of 15 g / kg); or the use of automatic welding instead of manual welding etc.4, in the weldi

11、ng process, why the manganese vapor and soot?When welding electrode of manganese in 5-7% in baking in the weld, more than 85% of the welding slag, Zhen is less than 10%, after the high temperature pyrolysis of the arc, oxidation by direct oxidation and replacement reaction, a manganese vapor (mainly

12、 manganese oxide aerosol) and coagulation of manganese dust become win.When welding, the flue gas and smoke of manganese mainly come from the electrode, but not to the manganese content of the base metal. The manganese content of the general acid welding rod is higher than that of the basic electrod

13、e, so the content of manganese in the welding aerosol formed by the welding of the acid welding electrode is higher than that of the basic electrode.5 、 what harmful gases are there around welding arc?In the welding arc under high temperature and strong ultraviolet radiation, the welding arc forms m

14、any kinds of poisonous gas around, mainly has: ozone, carbon monoxide, nitrogen oxide, hydrogen fluoride and so on.6, nitrogen oxide gas on the human body what are the hazards?Mainly irritating to the lungs. Mucous membrane of upper respiratory tract is stimulated little, the stimulation to the eye

15、also is not big, wont cause apparent stimulation symptom in general. A breakdown caused by chronic poisoning, upper respiratory tract inflammation, chronic bronchitis, acute poisoning, due to the high concentration of nitrogen oxides on the respiratory tract deep, so poisoning initially only caused

16、a mild eye and throat discomfort (stimulus), after the incubation period will occur, and even cause acute bronchitis, pulmonary edema, suction breath, weakness, malaise and other symptoms.7. How does hydrogen fluoride gas come into being? What harm does it have to the human body?Hydrogen fluoride ga

17、s is mainly produced in the electric arc welding and fluorspar in medicine, containing skin of low hydrogen electrodes (CaF2) and quartz (Si2), the formation of hydrogen fluoride gas in the arc under high temperature.Hydrogen fluoride is absorbed rapidly by the respiratory mucosa and can be absorbed

18、 by the skin and is toxic to the whole body. Inhalation of high concentrations of hydrogen fluoride gas or vapor, can immediately produce eyes nose and respiratory tract mucosa irritation caused by congestion, nasal and throat dry mucous membranes, nasal ulcers, severe bronchitis, pneumonia can occu

19、r.8. What kinds of arc are manual arc welding made of?Including infrared, strong visible light and ultraviolet three kinds, they are due to the heating of objects, belong to the hot wire spectrum.9, which kinds of wavelengths are there in ultraviolet light? What effect does it have to the skin? What

20、 kind of wavelength is most likely caused by electric ophthalmia?Manual arc welding can reach more than 3000 degrees of temperature and a large amount of ultraviolet light will be produced at this temperature. Ultraviolet light can be divided into three parts: long wave, medium wave and short wave.

21、Nagawa Naminaga is 400-320 microns, and the medium short wave length is 320-180 microns.Ultraviolet light of different wavelengths, absorbed by different depths of the skin tissue. The wavelength of 220 nm was almost below the cuticle absorption wavelength of 220-300 nm, for deep tissue really wave

22、absorption wavelength of 79-298 nm and 250 nm, the strongest effect on the skin. One thousand times for the wavelength of 366 nm.The skin is affected by strong ultraviolet radiation, can cause dermatitis, chronic erythema, and sometimes small blisters, exudate and edema, burning sensation, itching,

23、peeling. The shorter wavelengths of ultraviolet light, especially at 320 nm under ultraviolet light, can damage the cornea and conjunctiva, resulting in acute conjunctivitis, namely ophthalmia.10 main reasons, ophthalmia in what?(1) the same job site, several welding work at the same time, and the d

24、istance is too close, the middle and the lack of protective screen, the operator is near arc irradiation.(2) because of the unskilled technique, the protective mask is not worn before the arc is struck, and the mask is prematurely exposed before the arc is extinguished.(3) there is insufficient ligh

25、ting in the working area, so that the weld seam can not be seen so as to lead the arc first and then wear a face mask.(4) the irrelevant personnel are exposed to the strong light through the electric welding field.(5) because of the protective lens damage and leakage.11, arc in the infrared ray on t

26、he human body what are the effects?The harm of infrared rays on human body is mainly caused by the thermal effect of tissue. A sensation of heat. In the welding process, the eye by the infrared radiation strong, immediately felt a strong burning and burning, occurrence of flash illusion. Long term e

27、xposure to cataracts that can cause infrared rays, vision loss, and blindness in severe cases.12, high-frequency electromagnetic field on the human body what are the hazards? What safety measures should be taken?In order to rapidly ignite an arc, a high frequency oscillator is needed to excite the a

28、rc. The oscillator has a high frequency of 150-260 kHz and a voltage of up to 3500 volts. Because of the high frequency current of the oscillator, a high frequency electromagnetic field is formed in the space near the oscillator and the power transmission line, and the high-frequency electromagnetic

29、 field with high field strength for a long time has a certain influence on the human body. Usually cause dizziness, headache, fatigue, lack of memory, heart palpitations, chest tightness, weight loss, nervous breakdown and autonomic nerve dysfunction.In order to prevent the influence of high frequen

30、cy electromagnetic field on human body, the following safety measures should be taken:(1) reduce the time of the action of high frequency electromagnetic field, and then cut off the high frequency power supply (such as high frequency oscillator) immediately after arc ignition.(2) welding and welding

31、 cables are woven and shielded by metal and reliably grounded.(3) contact arc ignition or transistor pulse striking arc instead of high frequency arc striking.13, argon arc welding and plasma arc welding, what are the hazards of radioactive materials on the human body?,The use of gold in thorium tun

32、gsten electrode, is a natural radioactive material, from 90%. 10% rays, beta rays, 1%r rays, dust in thorium and its decay products of inhaled welding, it is difficult to exclude from the body, and the formation of irradiation. Chronic damage to the body. Radioactive materials often enter a small am

33、ount and accumulate in the body, it may cause lesions, causing the central nervous system, hematopoietic organ and digestive system diseases. Severe cases of radiation sickness.14, from which ways to eliminate the occupational hazards of welding operations?(1) change welding material and welding pro

34、cess;(2) strengthening mechanical transmission.(3) improve the working environment.(4) strengthen personal protection.(5) do a good job of health care.15, how to strengthen personal protection in welding?Personal protective measures include protection of the human eye, ear, mouth, nose, and all aspe

35、cts of the body. Among them, the general protection products are: overalls, gloves, shoes, glasses, masks, masks and so on. Special protective products are: air supply protective helmet, air supply closed helmet, air supply mask, molecular sieve, ozone masks, etc.16. What are the requirements of the

36、 welders work clothes?Shall comply with the provisions of GB9448-88 in 4.2.2 welding and cutting safety, i.e.:(1) cotton canvas overalls are widely used in general welding and cutting, and their working clothes are white in color. A white work coat with a flame retardant fabric on the surface is rec

37、ommended.(2) under the influence of ultraviolet radiation, gas shielded welding should be made of coarse wool or leather fabric in case of ozone and other gases, so as to prevent the welder from being scalded or increased in temperature during the operation.(3) welders engaged in all position welding shall be equipped with leather work clothes.(