Advanced Lubrication of
Steel Mill Components: A Solution for Extreme Conditions
Picture 1: bearing of caster runout table during annual inspection
Introduction
It is very difficult to lubricate machinery at the hot end of a steel plant. The high temperatures and the large amount of water needed to keep temperatures fairly moderate make it difficult to choose the right grease / lubricant for this kind of application. Automated lubrication equipment needs constant attention, downtime is very costly and breakdowns can result in safety concerns as well as quality issues. Cooling water failures can also adversely affect grease performance. The greases in the steel industry require a good number of properties in order to withstand the harsh conditions of the application, namely: • high load carrying capacity • improved wear protection
• excellent mechanical stability (with and without presence of water)
• outstanding water resistance • excellent corrosion inhibition
Lithium and lithium complex greases are used extensively in the steelmaking process, and are common even in critical applications that would benefit from a superior lubricant. Taking one of the most extreme applications, a continuous caster, Castrol has developed a grease that not only copes with this environment but has exceeded the expectations of production and maintenance teams when trialled by maximising component life.
Most standard greases, for example those based on a simple lithium soap, do not cope well with high temperatures. A
grease consists of a soap structure, oil as a lubricant and a small percentage of additives may be present for high load carrying capacity. At high temperatures the soap structure can quickly break down; this is called the dropping point, an irreversible process where the grease releases the lubricant and is therefore useless.
One option is to increase consumption rates. If low quality grease is pumped through an automatic lubrication system fast enough to not be affected by the high temperature, it will have more effect in lubricating the components. However, with waste costs rising and corporations signing up to be more environmentally friendly, this is not a preferred choice Another option is to use a lubricant designed for extreme temperatures. These lubricants are usually costly, and in certain applications may not give an end user the type of return they expect; lubricated components subjected to extreme heat are usually in areas where cooling water is present. This can wash off a lot of the grease, increasing consumption as well as waste stream costs.
Castrol’s Molub Alloy 6080 grease was specifically designed to meet the needs of components lubricated in extreme conditions. During initial testing, the lubricant was benchmarked against a number of widely available products to check performance before starting a live trial. Products with similar characteristics were selected, all at the high performance end of the lubricants market.
6
LUBE MAGAZINE NO.123 OCTOBER 2014
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65
