The Effects of Low Temperature on Steel – A Field Guide

By Jason Thompson

Jason is a partner and VP of Operations at Sparta Engineering (located in Linden, AB) and has been designing and managing the manufacturing of various oil field equipment ranging from period one double service rigs down to hole tools since 2005. Jason has a particular passion for optimizing design for manufacturing. He also specializes in various crane related activities including subframe design, crane deck design, load and stability testing and acting stamp engineer for Global Crane Inspection.

Jason publishes regularly on the Sparta Blog on topics relating to service rig design, using steel in low temperatures, rig stability and monitoring, and how to manage a successful engineering department, among others.

Connect with Jason on LinkedIn or send Jason a note.

Jason Thompson, P.Engjason@spartaengineering.com

Office: (587) 315-0344 Ext: 101

www.spartaengineering.com

The Effects of Low Temperature on Steel – A Field Guide The following is meant to be a field guide for dealing with steel at low temperatures:

1. Don’t Weld If the ambient temperature is lower than -18 degrees C (0 degrees F) you should not be welding on anything without an engineer’s approval. If the metal is cold, even if you are in a shop, you should pre-heat to at least 10 degrees C (50 degrees F) prior to welding.

2. Check Your Rigging

Most rigging equipment will come with a minimum operating temperature. Be aware of this minimum and if needed, purchase equipment with appropriate ratings.

3. Avoid Shock Loading Try and operate at a steady rate. Shock loading, sudden changes in direction, or any other type of incidental loading should be avoided.

4. Inspect Equipment Regularly Consider increasing inspection intervals when it is cold out. Frequent periodic inspection to look for cracking, nicks, or chipping will help prevent accidents. Increased frequency of NDT may also help.

5. Understand Brittle Failure (Ductile to Brittle Transition) When steel fails because of a change due to low temperature, it fails in a brittle manor. This is particularly dangerous in the field because brittle failures happen quickly and without much warning. The steel won’t bend and deform like it does in moderate temperature before breaking. Use care to stay out of danger - there won’t be a warning before something breaks. Also note: the maximum capacity doesn’t change (even though de-rating things is one way to protect yourself). It has more to do with shock loading and crack propagation.

Rigging Equipment Materials Forged and Cast -40° C Mild Steel -20° C

McKissick Blocks -20° C

Quenched and Tempered -40° C

Crosby "Cold Tuff" Products -40° C Aluminum

No effect

*taken from the crosby group catalog - use for reference

Stainless (200-300 series)

No effect

Stainless Steel (400 series) Caution