Tuesday, July 14, 2015

Future Trips

1.  Train ride from Beijing to Lhasa (Silk Road)

Beijing to Lhasa by train:

Beijing-Lhasa is 4,064 km, of which 1,110 km are over the newly-built Qinghai-Tibet railway
Train T27 will start from Beijing West Railway Station at 21:30 and arrive at Lhasa Railway Station at 20:58 on the third day after 47 hours and 28 minutes' running. Train T28 will depart from Lhasa Railway Station at 8:00 am. and arrive in Beijing west at 8:00 am on the third day with a 48-hour-trip.

Tibet Train Timetable

From-To Distance (km) Hard Seat Price Hard Sleeper Price Soft Sleeper Price
Beijing West-Lhasa 3753 389 Y (US$49) 813 Y (US$102) 1,262 Y(US$158)

 Beijing-Lhasa is 4,064 km, of which 1,110 km are over the newly-built Qinghai-Tibet railway.


Detailed Itinerary of Beijing to Lhasa Train
Stops Arrival Departure Stop Time (Mins) Day KM`s
West Beijing   20:09      
Shijiazhuang 22:44 22:46 02 Day1 277
 Taiyuan 00:53 01:01 08 Day 2 1200
 Zhongwei 07:33 07:41 15 Day 2 1200
Lanzhou 13:04 13:19 15 Day 2 1876
West Xining 15:50 16:10 20 Day 2 2092
Golmud 01:38 01:58 20 Day 3 2922
Nagchu 11:18 11:24 06 Day 3 3742
Lhasa 16:00 - - Day 3 4064

 Map of Xining to Lhasa Train Route

 Better Options :
  • fly to Xining (Siling in Tibetan), stay there at least 2-3 days, and then take the train to Lhasa, or
  • fly in to Lhasa and take the train out of Lhasa at the end of your visit

2.   Alaska

Tuesday, February 24, 2015

Purpose of hardening and tempering of knife steel

Hardening is a way of making the knife steel harder. By first heating the knife steel to between 1050 and 1090°C (1922 and 1994°F) and then quickly cooling (quenching) it, the knife steel will become much harder, but also more brittle.

To reduce the brittleness, the material is tempered, usually by heating it to 175–350°C (347–662°F) for 2 hours, which results in a hardness of 53–63 HRC and a good balance between sharpness retention, grindability and toughness.

Tempering should be carried out within a reasonable time after hardening, preferably within an hour or so. It is of vital importance that the blade should be allowed to cool to room temperature before tempering is started. The transformation to martensite will otherwise be interrupted and the hardening results may be impaired.

A higher tempering temperature will yield a somewhat softer material with higher toughness, whereas a lower tempering temperature will produce a harder and somewhat more brittle material, as shown by the figure below.

A camping knife or a survival knife, for example, may be tempered at 350°C (662°F) so that it will be able to withstand rough handling without breaking. On the other hand, if the knife is expected to keep a sharp edge, it can instead be tempered at 175°C (347°F) for maximum hardness.

Tempering temperatures below 175°C (347°F) should be used only in exceptional cases, when extreme demands are made on high hardness, since very low tempering temperatures will result in a very brittle material. Similarly, tempering temperatures above 350°C (662°F) should be avoided, since this could give rise to brittleness and reduced corrosion resistance. Note that if the tempered blade is exposed to temperatures above the tempering temperature (e.g. during grinding), the properties of the knife will be impaired.

Correctly performed hardening will result in a good balance between hardness, toughness and corrosion resistance of the finished knife blade.