| 摘要 |
A corrosion-resistant gas cylinder includes an electroless nickel-boron layer which overlap on the inside of a steel alloy container. The nickel-boron layer has the thickness of 20 micrometers and the air porosity of 0.1% or less. The electroless nickel-boron layer has the boron content of at least 1 wt% and the surface roughness of 5 micrometers or less. A washing process is performed by using a second step baking process to wash the surface of the nickel-boron layer before inducing liquefied gas to the gas cylinder. The nickel-boron layer practically reduces the contamination of liquefied corrosion gas stored in the gas cylinder by metal from a river wall under the nickel-boron layer. A metal contamination level is maintained to be less than the 55 ppb of iron, the 10 ppb of chrome, and the 5 ppb of nickel by weight in the liquefied corrosion gas stored in an electroless nickel-boron plating gas cylinder for long time. |
