A fifty litre seamless gas cylinder manufactured from a 34CrMo4 low carbon alloy steel which was in service for five years failed in an unexpected manner, causing severe damage. The cylinder was filled with a mixture of fluorine and nitrogen. The fluorine was first filled into the cylinder at a pressure of 4 MPa and then topped up with nitrogen at 14 MPa. The filled cylinder was then allowed a 90 min settling period before coupling. Unfortunately, 20 min into the allowed 90 min of settling period, the fracture occurred leading to an explosion and damage. The fractured cylinder was subjected to chemical analysis, microstructural analysis, mechanical testing and stress calculation analysis. The mechanical and material properties of the steel were found to be of good quality indicating good manufacturing and heat treatment practices. The stress analysis also indicated that the applied pressure was within the applicable limit of the material. It was however found that, the failure occurred due to fluorine attack (burning) of the steel.

由34CrMo4低碳合金钢制造的50升无缝气瓶已经使用了5年，其意外失效，从而造成了严重损坏。量筒中装有氟和氮的混合物。首先将氟在4 MPa的压力下填充到钢瓶中，然后在14 MPa的压力下充入氮气。然后将装满的钢瓶放置90分钟，然后再进行偶联。不幸的是，在允许的90分钟稳定时间的20分钟内，发生了断裂，导致爆炸和损坏。对断裂的圆柱体进行化学分析，显微组织分析，力学测试和应力计算分析。发现该钢的机械和材料性能具有良好的质量，表明良好的制造和热处理实践。应力分析还表明，施加的压力在材料的适用范围内。然而，发现该故障是由于钢的氟侵蚀（燃烧）而发生的。