KVA Stainless has introduced new technology to produce high-toughness seam-welded pipes for gas and oil production and pipelines.

“With this patented technology, high-strength structural items can now be created using martensitic stainless steel and used in a variety of applications, with significant performance and cost benefits,” says Douglas Gore, vice-president of sales and business development.

Recognising the need for low-cost, high-strength structural tubing and piping, KVA Stainless founder, Ed McCrink, and his team of engineers and metallurgists have implemented patented welding and thermal processing technologies to create seam-welded martensitic tubing and piping, which took over four years to develop and perfect.

Coming out of the Navy with no experience in heat treating, McCrink started his career as a salesman for a thermal processing company in Chicago, IL. Within a couple of years, McCrink left his employer to start his own heat treating company in 1953 and grew the company to become one of the largest thermal processors in the US, which specialised in bright annealing and bright hardening. Since successfully selling the Hi-Temp Inc plants in the 1970s, he has continuously pursued his vision of utilising commonly available martensitic stainless steels to reduce weight and increase strength in structures. “McCrink is 89 years old and still comes to work everyday and it looks like he will soon have his own putter shaft developed and manufactured using his technology,” says Gore.

KVA martensitic stainless steel (MSS) tube and pipe are low-cost, high-performance substitutes for traditional carbon steel, 12Cr and 13Cr materials. “KVA MSS  is the patented, original and only fully martensitic, high toughness seam-welded pipe, offering unsurpassed tensile strength, hardness and wear resistance as compared to common low-carbon corrosion resistant modifications such as: Duracorr; Cromgard; 3Cr12; 410S (UNS S41008); 409 (UNS S40920); 12Cr and13Cr,” the company stressed.

Sizes and specifications
KVA’s MSS pipes can be produced in standard sizes up to 36” and wall thickness up to 0.750”. Non-standard sizes are made upon request.

“KVA longitudinal seam-welded MSS can be produced fully hardened, fully annealed, or anywhere in between, at substantial cost savings over seamless 410 or 420 pipe. Typical properties of KVA’s MSS pipe:

Hardened: yield strength: 160 ksi (1,100 MPa); ultimate tensile strength: 205 ksi (1,400 MPa); hardness: 370-390 Brinell (40-42 C Rockwell); elongation: 8-9 per cent.

Annealed: yield strength: 45 ksi (300 MPa); ultimate tensile strength: 80 ksi (530 MPa); hardness: 130 Brinell (80 B Rockwell); elongation: 30+ per cent.

The introduction of KVA MSS for the transport, oil and gas pipelines is ideally suited for mildly corrosive, abrasive media applications such as oil sands, slurry pipelines and coal transport.

“The abrasion resistance of hardened KVA MSS tube and pipe is unmatched – maximising durability, reliability and reducing erosion-corrosion failures. KVA martensitic stainless tubing or piping can be produced with chromium content ranging from 11.5 wt per cent to 16 wt per cent, maximising production and service life while minimising cost,” the company said.

“Until recently, welding of martensitic stainless steel into tubing had been impossible because it would cold-crack in the heat-affected zone under mechanical straining and forming. For this reason, martensitic stainless has long been considered the most difficult of the five types of stainless to weld.

“KVA Stainless technology can benefit any market segment where component weight, strength and corrosion resistance are critical issues, providing a superior alternative to conventional materials,” the company said.