Ramsay Test Welding and Metal Working 4

Question 1

When performing GTAW (TIG) welding on 304 stainless steel, carbide precipitation (sensitization) is most likely to occur in the heat-affected zone when the metal is held between which temperature range?

Accepted Answer

800°F – 1,500°F (427°C – 816°C)

Answer

Sensitization in austenitic stainless steels like 304 occurs when chromium carbides precipitate at grain boundaries in the 800°F–1,500°F (427°C–816°C) range, depleting the surrounding zones of chromium and making them susceptible to intergranular corrosion. This is why low-carbon grades (304L) or stabilized grades (321, 347) are preferred in corrosive service.

Question 2

A welder is joining two pieces of HSLA (high-strength low-alloy) steel with a carbon equivalent (CE) of 0.48. According to standard preheat guidelines, what is the PRIMARY risk if adequate preheat is NOT applied?

Accepted Answer

Hydrogen-induced cracking (cold cracking) in the HAZ

Answer

A carbon equivalent of 0.48 indicates a hardenable steel that requires preheat to slow the cooling rate. Without adequate preheat, diffusible hydrogen from the welding process becomes trapped in the hardened martensite of the HAZ, leading to hydrogen-induced (cold) cracking hours or even days after welding. Hot cracking is a solidification issue unrelated to CE; nitrogen porosity and lamellar tearing have different root causes.

Question 3

During SMAW, a welder notices consistent 'wagon tracks' (two parallel linear indications) appearing on radiographic examination of completed welds. What is the MOST likely cause?

Accepted Answer

Slag entrapment from incomplete removal between passes

Answer

Wagon tracks on radiographs are a classic signature of inter-pass slag entrapment, where slag from a previous pass was not completely removed before depositing the next bead. The trapped slag appears as two parallel linear indications following the edges of the underlying bead. Tungsten inclusions are specific to GTAW; centerline cracks appear as single linear indications; toe fusion issues typically appear as single irregular lines.

Question 4

A machinist is measuring the outside diameter of a steel shaft using an outside micrometer and obtains a reading of 1.278 inches. After comparing with a calibrated gauge block, the micrometer consistently reads 0.003 inches high. The shaft's ACTUAL diameter is:

Accepted Answer

1.275 inches

Answer

If the micrometer reads 0.003 inches HIGH (over-reads), the actual measurement is the reading minus the error: 1.278 − 0.003 = 1.275 inches. This is a systematic zero error. Confusing the direction of correction is a common error — if the instrument reads high, the true value is lower than indicated.

Question 5

In flux-cored arc welding (FCAW), a welder switches from DCEP (electrode positive) to DCEN (electrode negative) while using a gas-shielded flux-cored wire. What is the MOST likely result?

Accepted Answer

Erratic arc behavior, poor fusion, and excessive spatter

Answer

Gas-shielded FCAW wires (E70T-1, E71T-1, etc.) are specifically designed for DCEP. Switching to DCEN disrupts the arc characteristics established by the flux chemistry, resulting in an unstable arc, poor penetration, excessive spatter, and degraded weld quality. Self-shielded wires (E71T-11) are designed for DCEN, but the two types are NOT interchangeable in polarity.

Ramsay Test Practice Test

Ramsay Test Practice Test

Ramsay Test Welding and Metal Working 4