Preface
With the development of production, welding technology and Welding Electrode more widely, at the same time, with the emergence of a variety of unsafe and unhealthy factors serious threat to welders and other production personnel safety and health.

The main hazards are as follows:

1, the process of welding and cutting work needs to flammable gases, pressure vessels and motor electrical contact;

2, the welding process will produce toxic gases, harmful dust, arc radiation, noise and radiation and so on.

Risk factors mentioned above, under certain conditions may cause an explosion, fire, burns, poisoning, electric ophthalmia and skin diseases such as occupational diseases. Addition, it may endanger the equipment, plant and around the safety of personnel, to the state and enterprises should not have losses. Many major and serious accidents was due to welding and cutting operations caused by illegal workers. This article discusses the wider application of the daily gas welding(Gas Shielded Welding Wire), arc welding characteristics, hazards and safe operation.

Gas welding
1, characteristics and hazards

Welding with simple equipment, easy, flexible, practical and so on.

Thus, in the manufacture and maintenance of the industrial sector more widely applied. However, this process takes advantage of combustible gases (such as: C2H2, LPG and H2, etc.), combustion gases (O2) and high pressure gas cylinders (such as: oxygen cylinders, acetylene bottles.) If the welding equipment and safety devices malfunction, or operator operating in violation of safe operation, and are likely to cause an explosion and fire and other accidents.

2, the use of safety requirements

1), industrial acetylene often contain phosphine (PH3), hydrogen sulfide (H2S) and other impurities, these impurities is not only easy to cause an explosion, and welding, in which the sulfur and phosphorus can be transferred to the weld metal in the weld change the mechanical properties, cold brittleness, thermal cracking tend to increase, the weld quality is difficult to guarantee. Therefore, by volume, requires the content of acetylene in the PH3 not exceed 0.2%; H2S content should be less than 0.1%.

2), gas cylinders in the storage and use, to avoid sun exposure, away from open flames and heat radiation.

3), the welding process, gas discharge rate should not be too fast, the gas flows through the valve to avoid static electricity spark.

4), acetylene bottles should be placed vertical stand, lying strictly prohibited place.

5), gas cylinders should be based on national "Gas Cylinder Safety Supervision Regulation," called for periodic technical inspections, extended use is strictly prohibited.

6), the operator should receive safety training certificates.

7), welding torch must be checked before use, including fire smoke case, hose connections and fittings, air leaks, the gas is the clean channel so only after checking the normal operation of the ignition. Use, to prevent tempering, tempering should immediately close the case of acetylene valve, while closing the oxygen valve.

SMAW
1, characteristics and hazards

SMAW is the most widely used industrial production welding method, the important reason is that the arc can effectively and easily convert the electrical energy needed to heat the welding process and mechanical energy. At the same time by hand manipulation of SMAW welding electrodes, can be all-position welding; welding equipment, portable, flexible transportation for all kinds of metal materials, various thickness, various structural forms of welding.
However, there will be less because of its specificity of insecurity:

1), arc arc core temperature of up to 6000 ~ 8000 ℃, welding rods, welding parts and coating at high temperature, the occurrence of evaporation, condensation and gas, resulting in a lot of smoke and dust;

2), arc strong ambient radiation in the arc, will produce ozone, nitrogen oxides and other toxic gases;

3), splash, welding line pipe welding failure or explosion-proof measures for fuel containers properly, will cause an explosion and fire accidents.

4), welding equipment, no-load voltage is higher than the safety of the human body can withstand voltage, high incidence of electric shock.
2, the use of safety requirements

1), welding machine must have a separate dedicated power switch, prohibit more than one welding machine share a power switch;

2), welding machine to prevent the collision, moisture or excessive vibration;

3), welding machine should be well exposed live parts of the protective device, the shell should be grounded not charged, non-overload;

4), welding cable jacket integrity, good insulation, you should use the whole conductor;

5), electrode holder must have good insulation, heat capacity, heat of the welding clamp is strictly prohibited under water immediately after cooling;

6), welding operations, the place should have ventilation and dust removal facilities, flammable, explosive material ignition sources away from the job should be not less than 10m;

7), good welding operations should wear labor protection products, to strengthen their protection, to ensure its own security.

In summary, the potential danger of the welding process, for staff engaged in the job requirements should be strictly and must be appropriate, specialized security technology theoretical study and practical training to improve the safety of such operations technology quality, and after passing an examination to obtain operating permits security technology behind the quasi-independent operations; the same time, through training so that they understand the welding characteristics of the basic principles of soldering and welding techniques, safe use of tools; strictly enforce safety rules and protective measures are implemented to ensure safety production, to avoid accidents.

keywords: welding electrode material