Q.1 A typical soil corrosion is aggravated under which which of the following conditions a. b. c. d.
Hgh moist moisture ure conten contentt and high high resisti resistivity vity of of soil. Hgh moist moisture ure conten contentt and low resis resistiv tivity ity of soil. soil. Low moist moisture ure conten contentt and high high resisti resistivity vity of of soil. soil. Low moist moisture ure conten contentt and low low resistiv resistivity ity of soil. soil.
Q.2 Typical Typical “high cycle fatigue is a. b. c. d.
Ther Therma mall fat fatig igue ue.. !ech !echani anica call fatigu fatigue. e. "ibr "ibrat atio ion n fati fatigu gue. e. #oth a and b. b.
Q.$ %eduction in li&elihood of brittle fracture can be obtained by performing a. b. c. d.
'mpa 'mpact ct tes testi tin ng Hydr Hydrost ostati atic c testin testing g ()HT (neu (neuma mati tic c test testin ing g
Q.* Thermal fatigue crac&s usually are a. b. c. d.
#ranching+ #ranching+ Transgr Transgranular anular and initiate initiate from from within within the material. ,agger shaped+ intergranular intergranular and and initiate initiate form form within the material. material. ,agger ,agger shaped shaped++ o-ide filled filled and and initiate initiate form form the surface. surface. ,agger ,agger shaped shaped++ clean clean and interg intergranu ranular lar..
Q. /rosion0orrosion mitigation can be achieved by a. b. c. d.
'ncreasi 'ncreasing ng the pipe pipe diameter diameter to decrea decrease se velocity velocity 'ncreasing 'ncreasing surface surface hardness hardness by using using harder harder alloys alloys or hard hard facing facing sing sing corrosio corrosion n resis resistant tant alloys alloys All All of of the the abov above. e.
Q.3 “lam shell4 type crac& failure having concentric rings called “beach mar&s4 showing “waves4 of crac& propagation is typically the description of a. b. c. d.
Q.7 %esistance to sulphidation is generally achieved by a. b. c. d.
pgrading to higher nic&el alloys pgrading to higher chromium alloys pgrading to higher copper based alloys All of the above.
Q.8 haracteristic hloride 6 in Austenitic 6.6. generally will be a. Transgranular+ branching and aggravated by reduced temperature below ambient temperature. b. 'ntergranular and unidirectional 9straight: and aggravated by increasing temperature c. 'ndependent of chloride content d. ;one of the above
Q.< austic embrittlement may be reduced0prevented by a. b. c. d.
Q.1> a. b. c. d.
onducting ()HT. pgrading to ;ic&el alloys. sing High hardness = High strength steels. #oth a and b.
High temperature hydrogen attac& is typically due to !ethane gas formation. )et H26 formation Temper embrittlement (resence of !olybdenum in alloy steels.
PRACTICE QUESTIONS-Closed Book (API 571) Q.1 'f alloy steels have undergone “temper embrittlement4 + the appropriate testing to confirm the same is
Q.* Thermal fatigue crac&s usually are e. f. g. h.
#ranching+ Transgranular and initiate from within the material. ,agger shaped+ intergranular and initiate form within the material. ,agger shaped+ o-ide filled and initiate form the surface. ,agger shaped+ clean and intergranular.
Q. /rosion0orrosion mitigation can be achieved by e. f. g. h.
'ncreasing the pipe diameter to decrease velocity 'ncreasing surface hardness by using harder alloys or hard facing sing corrosion resistant alloys All of the above.
Q.3 “lam shell4 type crac& failure having concentric rings called “beach mar&s4 showing “waves4 of crac& propagation is typically the description of e. 5atigue crac&s. f. reep crac&s. g. 6tress corrosion crac&s. h. Hydrogen induced crac&s. Q.7 %esistance to sulphidation is generally achieved by e. pgrading to higher nic&el alloys
f. pgrading to higher chromium alloys g. pgrading to higher copper based alloys h. All of the above.
Q.8 haracteristic 6 in Austenitic 6.6. generally will be e. Transgranular+ branching and aggravated by reduced temperature below ambient temperature. f. 'ntergranular and unidirectional 9straight: and aggravated by increasing temperature g. 'ndependent of chloride content h. ;one of the above
Q.< 'dentify the correct statement 9s: e. 66 is aggravated due to wet H 26 f. Hydrogen blistering may occur on '.,+ D.,+ or any where within wall thic&ness of the pressure vessel. g. High hardness = High strength steels are more li&ely to undergo damage due to wet H 26 compared to low strength0 low hardness steels h. All of the above are correct statements Q.1> High temperature hydrogen attac& is typically due to e. !ethane gas formation. f. )et H26 formation g. Temper embrittlement (resence of !olybdenum in alloy steels
