... sparktechnique: casting or forgingsurface treatment:mirror polishedapplication: petroleum,chemical industry,power generation,railway,mining,etc. ... petroleum, chemicalindustry, electronics, railway, shipbuilding, metallurgy, boiler, mine, gas production, power generation, storage andtransportation, pharmacy, gas production, wine production, leather, plastic, fireworks, gunpowder, liquefied gas, gas ...